Mono: 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	45,086	2424.7	− 2436	−11.3	× 146 / 890	−1.9
4	45,087	2464.4	− 2485	−20.6	× 122 / 890	−2.8
5	45,090	2489.5	− 2528	−38.5	× 125 / 890	−5.4
6	45,091	2525.8	− 2552	−26.2	× 114 / 890	−3.4
7	45,094	2535.1	− 2567	−31.9	× 113 / 890	−4.1
8	45,095	2536.9	− 2586	−49.1	× 143 / 890	−7.9
11	45,098	2540.1	− 2628	−87.9	× 127 / 890	−12.5
Sum, rounded to a whole point						−38

2016 from sb_ca2016_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	41,794	2410.4	− 2436	−25.6	× 120 / 861	−3.6
4	41,795	2465.0	− 2485	−20	× 143 / 861	−3.3
5	41,797	2489.6	− 2528	−38.4	× 126 / 861	−5.6
6	41,799	2533.7	− 2552	−18.3	× 117 / 861	−2.5
7	41,802	2534.0	− 2567	−33	× 118 / 861	−4.5
8	41,803	2571.2	− 2586	−14.8	× 115 / 861	−2
11	41,805	2550.1	− 2628	−77.9	× 122 / 861	−11
Sum, rounded to a whole point						−33

2017 from sb_ca2017_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	42,831	2403.9	− 2436	−32.1	× 117 / 844	−4.4
4	42,832	2427.6	− 2485	−57.4	× 127 / 844	−8.6
5	42,834	2470.3	− 2528	−57.7	× 141 / 844	−9.6
6	42,837	2518.4	− 2552	−33.6	× 128 / 844	−5.1
7	42,838	2524.2	− 2567	−42.8	× 124 / 844	−6.3
8	42,841	2560.0	− 2586	−26	× 118 / 844	−3.6
11	42,843	2549.8	− 2628	−78.2	× 89 / 844	−8.2
Sum, rounded to a whole point						−46

2018 from sb_ca2018_1_csv_v3.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	42,845	2400.3	− 2436	−35.7	× 119 / 884	−4.8
4	42,848	2429.0	− 2485	−56	× 116 / 884	−7.3
5	42,849	2464.6	− 2528	−63.4	× 122 / 884	−8.7
6	42,852	2531.6	− 2552	−20.4	× 135 / 884	−3.1
7	42,853	2536.9	− 2567	−30.1	× 130 / 884	−4.4
8	42,856	2557.6	− 2586	−28.4	× 130 / 884	−4.2
11	42,857	2544.6	− 2628	−83.4	× 132 / 884	−12.5
Sum, rounded to a whole point						−45

2019 from sb_ca2019_1_csv_v4.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	42,961	2425.9	− 2436	−10.1	× 123 / 845	−1.5
4	42,962	2433.4	− 2485	−51.6	× 103 / 845	−6.3
5	42,963	2471.5	− 2528	−56.5	× 122 / 845	−8.2
6	42,964	2521.5	− 2552	−30.5	× 122 / 845	−4.4
7	42,965	2543.8	− 2567	−23.2	× 140 / 845	−3.8
8	42,966	2576.2	− 2586	−9.8	× 128 / 845	−1.5
11	42,967	2560.2	− 2628	−67.8	× 107 / 845	−8.6
Sum, rounded to a whole point						−34

2021 from sb_ca2021_1_csv_v2.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	41,835	2426.5	− 2436	−9.5	× 39 / 262	−1.4
4	41,836	2451.3	− 2485	−33.7	× 24 / 262	−3.1
5	41,837	2505.6	− 2528	−22.4	× 34 / 262	−2.9
6	41,838	2510.3	− 2552	−41.7	× 18 / 262	−2.9
7	41,839	2526.0	− 2567	−41	× 26 / 262	−4.1
8	41,840	2537.2	− 2586	−48.8	× 24 / 262	−4.5
11	41,841	2559.9	− 2628	−68.1	× 97 / 262	−25.2
Sum, rounded to a whole point						−44

2022 from sb_ca2022_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	42,696	2396.1	− 2436	−39.9	× 114 / 737	−6.2
4	42,697	2447.8	− 2485	−37.2	× 114 / 737	−5.8
5	42,698	2472.7	− 2528	−55.3	× 96 / 737	−7.2
6	42,699	2514.5	− 2552	−37.5	× 111 / 737	−5.6
7	42,700	2521.3	− 2567	−45.7	× 95 / 737	−5.9
8	42,701	2553.7	− 2586	−32.3	× 102 / 737	−4.5
11	42,702	2562.6	− 2628	−65.4	× 105 / 737	−9.3
Sum, rounded to a whole point						−44

2023 from sb_ca2023_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	42,709	2410.2	− 2436	−25.8	× 118 / 780	−3.9
4	42,710	2432.4	− 2485	−52.6	× 120 / 780	−8.1
5	42,711	2466.7	− 2528	−61.3	× 110 / 780	−8.6
6	42,712	2525.5	− 2552	−26.5	× 95 / 780	−3.2
7	42,713	2537.7	− 2567	−29.3	× 110 / 780	−4.1
8	42,714	2526.6	− 2586	−59.4	× 96 / 780	−7.3
11	42,715	2546.4	− 2628	−81.6	× 131 / 780	−13.7
Sum, rounded to a whole point						−49

2024 from sb_ca2024_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	42,542	2421.4	− 2436	−14.6	× 126 / 773	−2.4
4	42,543	2453.6	− 2485	−31.4	× 120 / 773	−4.9
5	42,544	2457.4	− 2528	−70.6	× 119 / 773	−10.9
6	42,545	2513.9	− 2552	−38.1	× 113 / 773	−5.6
7	42,546	2542.9	− 2567	−24.1	× 88 / 773	−2.7
8	42,547	2544.8	− 2586	−41.2	× 106 / 773	−5.6
11	42,548	2539.4	− 2628	−88.6	× 101 / 773	−11.6
Sum, rounded to a whole point						−44

2025 from sb_ca2025_1_csv_v1.zip

Grade	Line in file	Average score	Standard Met	Distance	Students	Weighted
3	42,301	2411.2	− 2436	−24.8	× 95 / 733	−3.2
4	42,302	2439.9	− 2485	−45.1	× 121 / 733	−7.4
5	42,303	2474.8	− 2528	−53.2	× 115 / 733	−8.3
6	42,304	2505.2	− 2552	−46.8	× 108 / 733	−6.9
7	42,305	2519.2	− 2567	−47.8	× 114 / 733	−7.4
8	42,306	2535.0	− 2586	−51	× 87 / 733	−6.1
11	42,307	2540.4	− 2628	−87.6	× 93 / 733	−11.1
Sum, rounded to a whole point						−51

Step 2 · The average and the normal range

Average: add the yearly results and divide by how many there are. −38, −33, −46, −45, −34, −44, −44, −49, −44, −51 → −42.8
Typical year-to-year change: how far the result moved from each year to the next, ignoring up or down. 2015→2016: 5 · 2016→2017: 13 · 2017→2018: 1 · 2018→2019: 11 · 2019→2021: 10 · 2021→2022: 0 · 2022→2023: 5 · 2023→2024: 5 · 2024→2025: 7 → average 6.3
Normal range: multiply the typical change by 2.66, then add it to the average and subtract it. 6.3 × 2.66 = 16.8. Upper limit −26, lower limit −59.6.

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.