CREATE TABLE table_65662 ("School" TEXT, "City" TEXT, "Mascot" TEXT, "County" TEXT, "Year joined" FLOAT, "Previous Conference" TEXT, "Year Left" FLOAT, "Conference Joined" TEXT)

What is the year that the Roughriders left the conference?
SELECT MAX("Year Left") FROM table_65662 WHERE "Mascot" = 'roughriders'
SELECT MAX("Year Left") FROM "table_65662" WHERE "Mascot" = 'roughriders'