The Eagles returned home to square off against the favored Baltimore Ravens in a Battle of the Birds.  Eagles' running back LeSean McCoy opened the scoring with a 1-yard touchdown run some ten minutes into the first quarter for a 7-0 lead.  However, the Ravens were able to tie the game up at 7-7 with Vonta Leach running for a 5-yard touchdown.  They would take the lead in the 2nd quarter as Joe Flacco found Jacoby Jones on a 21-yard touchdown pass to take a 14-7 lead followed by a 56-yard field goal by Justin Tucker for a 17-7 lead just before halftime.  The 3rd quarter was all Eagles as they managed to catch up with Michael Vick's 23-yard touchdown pass to Jeremy Maclin to make the score 17-14 and then tied the game with Alex Henery's 23-yard field goal at 17-17.  However, the Ravens moved back into the lead in the 4th quarter as Tucker was able to score 2 long field goals from 51 and 48 yards out to make the score 20-17 and 23-17 respectively.  The Eagles came out and surprisingly won the game with Vick's 1-yard QB rushing touchdown as the Eagles managed to win the game 24-23. With the win, the Eagles improved to 2-0 and became the first team in NFL history to start a season 2-0 after winning their first 2 games by only a point.
Question: How many points did the Ravens lead by at halftime?
Answer: 10