Purpose: Stores general performance information for a question (date, cohort size, etc).
Joins: questions and properties tables

idint(11)Auto increment field for the table
q_idint(10) unsignedID of the question
paperIDint(10) unsignedID of the paper
percentagetinyint(4)Percentage size used to run the Frequency/Discrimination Analysis report.
cohort_sizeint(10) unsignedHow many students took the exam.
takendateDate the exam was taken.