CREATE TABLE table_24153 ("Outcome" CLOB, "Year" FLOAT, "Championship" CLOB, "Surface" CLOB, "Partner" CLOB, "Opponents in the final" CLOB, "Score in the final" CLOB)

What was the court surface on year 1971?
SELECT "Surface" FROM table_24153 WHERE "Year" = '1971'
SELECT "Surface" FROM "table_24153" WHERE "Year" = '1971'