CREATE TABLE table_203_7 (id NUMBER, "pos." NUMBER, "artist" CLOB, "single" CLOB, "year" NUMBER, "sales" NUMBER, "peak" NUMBER)

how many more sales did elton john have than lou bega ?
SELECT (SELECT "sales" FROM table_203_7 WHERE "artist" = 'elton john') - (SELECT "sales" FROM table_203_7 WHERE "artist" = 'lou bega')
SELECT (SELECT "sales" FROM "table_203_7" WHERE "artist" = 'elton john') - (SELECT "sales" FROM "table_203_7" WHERE "artist" = 'lou bega')