CREATE TABLE table_203_198 (id DECIMAL, "season" TEXT, "series" TEXT, "team" TEXT, "races" DECIMAL, "wins" DECIMAL, "poles" DECIMAL, "fast laps" DECIMAL, "points" DECIMAL, "pos." TEXT)

what is the only series listed in 2007-2008 ?
SELECT "series" FROM table_203_198 WHERE "season" = '2007-08'
SELECT "series" FROM "table_203_198" WHERE "season" = '2007-08'