CREATE TABLE table_48909 ("Year" TEXT, "Starts" FLOAT, "Wins" FLOAT, "Top 5" FLOAT, "Top 10" FLOAT, "Poles" FLOAT, "Avg. Start" FLOAT, "Avg. Finish" FLOAT, "Position" TEXT)

WHAT IS THE LOWEST AVERAGE FINISH FOR 40TH POSITION, WITH A TOP 5 LARGER THAN 0?
SELECT MIN("Avg. Finish") FROM table_48909 WHERE "Position" = '40th' AND "Top 5" > '0'
SELECT MIN("Avg. Finish") FROM "table_48909" WHERE "Position" = '40th' AND "Top 5" > '0'