Hoping to rebound from their divisional loss to the Cardinals the Rams flew to Oakland-Alameda County Coliseum for an Interconference duel with the Oakland Raiders. In the 2nd quarter the Rams would score first with QB Sam Bradford making a 7-yard TD pass to WR Mark Clayton. Then the Raiders replied with kicker Sebastian Janikowski nailing a 38-yard field goal; then he booted a 41-yard field goal in the third quarter. Then the Rams fell behind when QB Bruce Gradkowski made a 4-yard TD pass to WR Louis Murphy, followed in the fourth quarter by Janikowski nailing a 22-yard field goal. The Rams cut the lead when Bradford found WR Mark Clayton on a 17-yard TD pass, but couldn't pull out the victory. With the close loss and 13th straight loss to an AFC opponent, the Rams fell to 0-2.

Based on the above article, answer a question. How many more total touchdown passing yards did Sam Bradford have than Bruce Gradkowski?
20