CREATE TABLE table_24627 ("Year" FLOAT, "Starts" FLOAT, "Wins" FLOAT, "Top 5" FLOAT, "Top 10" FLOAT, "Poles" FLOAT, "Avg. Start" CLOB, "Avg. Finish" CLOB, "Winnings" CLOB, "Position" CLOB, "Team ( s ) " CLOB)

Name the number of years for 18.5
SELECT COUNT("Year") FROM table_24627 WHERE "Avg. Finish" = '18.5'
SELECT COUNT("Year") FROM "table_24627" WHERE "Avg. Finish" = '18.5'