CREATE TABLE table_203_237 (id DECIMAL, "n" DECIMAL, "p" TEXT, "nat." TEXT, "name" TEXT, "age" DECIMAL, "moving from" TEXT, "type" TEXT, "transfer\ window" TEXT, "ends" DECIMAL, "transfer\ fee" TEXT)

what is the difference in age between palo vanoli and marc kalenga ?
SELECT (SELECT "age" FROM table_203_237 WHERE "name" = 'paolo vanoli') - (SELECT "age" FROM table_203_237 WHERE "name" = 'marc kalenga')
SELECT (SELECT "age" FROM "table_203_237" WHERE "name" = 'paolo vanoli') - (SELECT "age" FROM "table_203_237" WHERE "name" = 'marc kalenga')