CREATE TABLE track (Track_ID NUMBER, Name CLOB, Location CLOB, Seating FLOAT, Year_Opened FLOAT)
CREATE TABLE race (Race_ID NUMBER, Name CLOB, Class CLOB, Date CLOB, Track_ID CLOB)

Compute the total the total number across class as a pie chart.
SELECT Class, COUNT(*) FROM race GROUP BY Class
SELECT "Class", COUNT(*) FROM "race" GROUP BY "Class"