CREATE TABLE table_203_834 (id DECIMAL, "rank" DECIMAL, "census subdivision" TEXT, "province" TEXT, "type" TEXT, "land area\ ( km2 ,  2011 ) " DECIMAL, "population 2011" DECIMAL, "population 2006" DECIMAL, "population 2001" DECIMAL, "population 1996" DECIMAL, "change in % 2006-2011" DECIMAL, "change in % 1996-2011" DECIMAL)

of the top 10 most heavily populated census subdivisions in 2011 , how many located were in ontario ?
SELECT COUNT("census subdivision") FROM table_203_834 WHERE "population 2011" IN (SELECT "population 2011" FROM table_203_834 ORDER BY "population 2011" DESC LIMIT 10) AND "province" = 'ontario'
SELECT COUNT("census subdivision") FROM "table_203_834" WHERE "population 2011" IN (SELECT "population 2011" FROM "table_203_834" ORDER BY "population 2011" DESC NULLS LAST LIMIT 10) AND "province" = 'ontario'