CREATE TABLE table_4283 ("Umpire" TEXT, "Country" TEXT, "Panel" TEXT, "Matches" FLOAT, "WC Matches" FLOAT, "2011 WC" FLOAT)

in which country whe wc maches was 15
SELECT "Country" FROM table_4283 WHERE "WC Matches" = '15'
SELECT "Country" FROM "table_4283" WHERE "WC Matches" = '15'