CREATE TABLE table_204_542 (id NUMBER, "season" CLOB, "competition" CLOB, "round" CLOB, "club" CLOB, "home" CLOB, "away" CLOB, "aggregate" CLOB)

what is the number of countries that played during the 2011-12 uefa europa league ?
SELECT COUNT("club") FROM table_204_542 WHERE "season" = '2011-12'
SELECT COUNT("club") FROM "table_204_542" WHERE "season" = '2011-12'