CREATE TABLE table_24642 ("Year" FLOAT, "Starts" FLOAT, "Wins" FLOAT, "Top 5" FLOAT, "Top 10" FLOAT, "Poles" FLOAT, "Avg. Start" TEXT, "Avg. Finish" TEXT, "Winnings" TEXT, "Position" TEXT, "Team ( s ) " TEXT)

How many different teams had an average start of 12.9?
SELECT COUNT("Team(s)") FROM table_24642 WHERE "Avg. Start" = '12.9'
SELECT COUNT("Team(s)") FROM "table_24642" WHERE "Avg. Start" = '12.9'