After a road win, the Steelers returned home to take on the Ravens.  The Steelers scored first in the first quarter as Ben Roethlisberger hooked up with Heath Miller on a 3-yard touchdown pass making the score 7-0.  Justin Tucker then got the Ravens on the board after nailing a 36-yard field goal shortening the lead to 7-3.  In the 2nd quarter, the Steelers moved ahead by a touchdown as Shaun Suisham nailed a 34-yard field goal to make the score 10-3.  The Ravens moved within 4 as Tucker nailed a 38-yard field goal for a 10-6 game at halftime with the Steelers leading.  After the break, the Steelers went back to work in the 3rd quarter as Suisham kicked a 28-yard field goal for a 13-6 lead.  The Ravens drew within 4 points again in the fourth quarter as Tucker kicked a 32-yard field goal for a 13-9 score.  Again, the Steelers retaliated and moved ahead by 7 points as Suisham kicked a 38-yard field goal for a 16-9 lead.  However, Joe Flacco was able to find Dallas Clark on a 1-yard touchdown pass tying the game at 16-16.  The Steelers managed to drive down the field for the game-winning field goal as Suisham nailed it from 42 yards out for a final score of 19-16 sending the Steelers to a 2-4 start.
Question: How many points did the Ravens trail by at halftime?
Answer: 4