Lake: math · Schoolio

The shaded band is this county's normal range. If nothing about how it works changes, nearly every future year should land inside it. Zero means the typical student just meets the state standard. The small numbers under the years are how many students were tested.

Step 1 · Each year's result

For each grade tested, take the average (mean) scale score from the California Department of Education's results file, and subtract the lowest score that counts as "Standard Met" for that grade. That is the grade's distance from standard. Weight each grade by its share of the students tested, then add the grades up. Grades where the state hides the average because ten or fewer students tested are left out entirely.

2015 from sb_ca2015_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	19,222	2386.9	− 2436	−49.1	× 684 / 4558	−7.4
4	19,225	2424.1	− 2485	−60.9	× 713 / 4558	−9.5
5	19,226	2445.5	− 2528	−82.5	× 653 / 4558	−11.8
6	19,229	2472.3	− 2552	−79.7	× 686 / 4558	−12
7	19,230	2491.4	− 2567	−75.6	× 643 / 4558	−10.7
8	19,233	2488.1	− 2586	−97.9	× 615 / 4558	−13.2
11	19,234	2532.3	− 2628	−95.7	× 564 / 4558	−11.8
Sum, rounded to a whole point						−76

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,240	2389.3	− 2436	−46.7	× 661 / 4670	−6.6
4	18,241	2415.9	− 2485	−69.1	× 686 / 4670	−10.2
5	18,244	2442.6	− 2528	−85.4	× 720 / 4670	−13.2
6	18,245	2464.1	− 2552	−87.9	× 673 / 4670	−12.7
7	18,247	2490.9	− 2567	−76.1	× 687 / 4670	−11.2
8	18,250	2498.3	− 2586	−87.7	× 630 / 4670	−11.8
11	18,251	2516.9	− 2628	−111.1	× 613 / 4670	−14.6
Sum, rounded to a whole point						−80

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,566	2396.0	− 2436	−40	× 682 / 4758	−5.7
4	18,567	2426.8	− 2485	−58.2	× 675 / 4758	−8.3
5	18,570	2433.2	− 2528	−94.8	× 689 / 4758	−13.7
6	18,571	2469.4	− 2552	−82.6	× 743 / 4758	−12.9
7	18,574	2479.5	− 2567	−87.5	× 658 / 4758	−12.1
8	18,575	2497.3	− 2586	−88.7	× 673 / 4758	−12.5
11	18,577	2514.6	− 2628	−113.4	× 638 / 4758	−15.2
Sum, rounded to a whole point						−80

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,599	2398.8	− 2436	−37.2	× 683 / 4741	−5.4
4	18,600	2431.0	− 2485	−54	× 692 / 4741	−7.9
5	18,603	2447.9	− 2528	−80.1	× 677 / 4741	−11.4
6	18,604	2459.6	− 2552	−92.4	× 696 / 4741	−13.6
7	18,607	2482.3	− 2567	−84.7	× 721 / 4741	−12.9
8	18,608	2491.7	− 2586	−94.3	× 664 / 4741	−13.2
11	18,611	2505.5	− 2628	−122.5	× 608 / 4741	−15.7
Sum, rounded to a whole point						−80

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,735	2394.1	− 2436	−41.9	× 694 / 4870	−6
4	18,736	2437.0	− 2485	−48	× 690 / 4870	−6.8
5	18,737	2451.1	− 2528	−76.9	× 698 / 4870	−11
6	18,738	2468.6	− 2552	−83.4	× 683 / 4870	−11.7
7	18,739	2475.5	− 2567	−91.5	× 715 / 4870	−13.4
8	18,740	2482.5	− 2586	−103.5	× 734 / 4870	−15.6
11	18,741	2501.7	− 2628	−126.3	× 656 / 4870	−17
Sum, rounded to a whole point						−82

2021 from sb_ca2021_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,276	2373.2	− 2436	−62.8	× 482 / 3236	−9.4
4	18,277	2407.0	− 2485	−78	× 476 / 3236	−11.5
5	18,278	2425.2	− 2528	−102.8	× 479 / 3236	−15.2
6	18,279	2443.5	− 2552	−108.5	× 456 / 3236	−15.3
7	18,280	2460.6	− 2567	−106.4	× 469 / 3236	−15.4
8	18,281	2467.4	− 2586	−118.6	× 416 / 3236	−15.2
11	18,282	2492.4	− 2628	−135.6	× 458 / 3236	−19.2
Sum, rounded to a whole point						−101

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,780	2376.9	− 2436	−59.1	× 722 / 4746	−9
4	18,781	2402.2	− 2485	−82.8	× 671 / 4746	−11.7
5	18,782	2422.5	− 2528	−105.5	× 721 / 4746	−16
6	18,783	2440.4	− 2552	−111.6	× 676 / 4746	−15.9
7	18,784	2459.3	− 2567	−107.7	× 670 / 4746	−15.2
8	18,785	2444.4	− 2586	−141.6	× 683 / 4746	−20.4
11	18,786	2477.0	− 2628	−151	× 603 / 4746	−19.2
Sum, rounded to a whole point						−107

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,727	2380.1	− 2436	−55.9	× 753 / 4969	−8.5
4	18,728	2403.1	− 2485	−81.9	× 747 / 4969	−12.3
5	18,729	2414.2	− 2528	−113.8	× 689 / 4969	−15.8
6	18,730	2436.9	− 2552	−115.1	× 759 / 4969	−17.6
7	18,731	2446.2	− 2567	−120.8	× 704 / 4969	−17.1
8	18,732	2446.3	− 2586	−139.7	× 695 / 4969	−19.5
11	18,733	2474.7	− 2628	−153.3	× 622 / 4969	−19.2
Sum, rounded to a whole point						−110

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,683	2380.2	− 2436	−55.8	× 759 / 5079	−8.3
4	18,684	2405.4	− 2485	−79.6	× 782 / 5079	−12.3
5	18,685	2421.6	− 2528	−106.4	× 738 / 5079	−15.5
6	18,686	2437.2	− 2552	−114.8	× 709 / 5079	−16
7	18,687	2447.0	− 2567	−120	× 747 / 5079	−17.6
8	18,688	2450.8	− 2586	−135.2	× 689 / 5079	−18.3
11	18,689	2473.7	− 2628	−154.3	× 655 / 5079	−19.9
Sum, rounded to a whole point						−108

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,682	2381.7	− 2436	−54.3	× 761 / 5180	−8
4	18,683	2414.2	− 2485	−70.8	× 744 / 5180	−10.2
5	18,684	2421.2	− 2528	−106.8	× 790 / 5180	−16.3
6	18,685	2430.6	− 2552	−121.4	× 750 / 5180	−17.6
7	18,686	2445.8	− 2567	−121.2	× 702 / 5180	−16.4
8	18,687	2453.2	− 2586	−132.8	× 747 / 5180	−19.2
11	18,688	2475.6	− 2628	−152.4	× 686 / 5180	−20.2
Sum, rounded to a whole point						−108

2026 from sb_ca2026_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	18,707	2387.2	− 2436	−48.8	× 758 / 5166	−7.2
4	18,708	2412.8	− 2485	−72.2	× 757 / 5166	−10.6
5	18,709	2430.3	− 2528	−97.7	× 747 / 5166	−14.1
6	18,710	2438.0	− 2552	−114	× 783 / 5166	−17.3
7	18,711	2441.6	− 2567	−125.4	× 741 / 5166	−18
8	18,712	2454.9	− 2586	−131.1	× 704 / 5166	−17.9
11	18,713	2474.3	− 2628	−153.7	× 676 / 5166	−20.1
Sum, rounded to a whole point						−105

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −76, −80, −80, −80, −82, −101, −107, −110, −108, −108, −105 → −94.3
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 4 · 2016→2017: 0 · 2017→2018: 0 · 2018→2019: 2 · 2019→2021: 19 · 2021→2022: 6 · 2022→2023: 3 · 2023→2024: 2 · 2024→2025: 0 · 2025→2026: 3 → average 3.9
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 3.9 × 2.66 = 10.4. Upper limit −83.9, lower limit −104.7.

Why 2.66? It is the standard factor from quality control, the work of Walter Shewhart and W. Edwards Deming. It turns "how much the result typically changes in a year" into "how far it can wander by chance alone".

Years with no result (no state tests were given in spring 2020) are skipped: the year-to-year change runs from the last year with a result to the next one.

Step 3 · Free or reduced-price meals

The share of enrolled students eligible for free or reduced-price meals — for a county, the total across its schools. From 2014–15, 2015–16, 2016–17, 2017–18, 2018–19, 2020–21, 2021–22, 2022–23, 2023–24, 2024–25, 2025–26.