CREATE TABLE table_71924 ("Year" TEXT, "Start" TEXT, "Qual" TEXT, "Rank" TEXT, "Finish" TEXT, "Laps" FLOAT)

What is the lap number for the rank of 13?
SELECT "Laps" FROM table_71924 WHERE "Rank" = '13'
SELECT "Laps" FROM "table_71924" WHERE "Rank" = '13'