CREATE TABLE table_68100 ("Year" FLOAT, "Entrant" TEXT, "Chassis" TEXT, "Engine" TEXT, "Points" FLOAT)

Which year is that has a Entrant of belond equa-flow / calif. muffler?
SELECT "Year" FROM table_68100 WHERE "Entrant" = 'belond equa-flow / calif. muffler'
SELECT "Year" FROM "table_68100" WHERE "Entrant" = 'belond equa-flow / calif. muffler'