Values between 1 and 10 (inclusive) were suppressed/removed for a given geography and replaced with the value ‘-999’ or ‘-999.00%’. Secondary suppression occurred in instances where a data element could be used to calculate a related value that was suppressed (e.g., when a numerator was suppressed for a calculation, the denominator and resulting value from the calculation were suppressed). When suppression of one case within a group of cases (e.g., graduation count for a single high school for a year) could result in reverse calculation of suppressed values, secondary suppression was applied to the next case with lowest value (e.g. the high school with the next lowest graduation count was suppressed for the same school year). The suppression rules were enforced to prevent the identification of individuals in an effort to preserve privacy and confidentiality.
The high school cohort graduation rates were calculated using the following formula:
([High School Graduation Cohort Count for the School Year] / [Ninth Grade Cohort Count]) * 100
The high school cohort includes students from the time they enter grade nine to graduation. Students who graduate within four years are considered on-time graduates. Students who transfer into a school are included in the cohort, while students who transfer out are dropped from the cohort.