The Steelers stayed home for a 3-game home stand and for a Sunday Night duel against the Ravens.  The Ravens scored first when Joe Flacco hooked up with Torrey Smith 35-yard TD pass to take a 7-0 lead for the only score of the first quarter.  In the 2nd quarter, the Steelers managed to tie the game up when Ben Roethlisberger found Le'Veon Bell on a 5-yard TD pass for a 7-7 game.  They eventually took the lead when Roethlisberger found Martavis Bryant on a 19-yard TD pass to make it a 14-7 game.  The Ravens came within 4 as Justin Tucker kicked a 46-yard field goal to make it 14-10 game.  However, the Steelers would manage to go ahead by 12 before halftime when Roethlisberger found Markus Wheaton on a 47-yard TD pass followed by a successful 2-point conversion for a 22-10 lead at halftime.  After a scoreless 3rd quarter, the Steelers came out strong and went back to work in the 4th when Roethlisberger found Antonio Brown on a 54-yard TD pass making the score 29-10.  The Ravens responded with a big play as Jacoby Jones ran a 108-yard kickoff return for a TD to make it a 29-17 game. Roethlisberger found Bryant again on an 18-yard TD pass to make the score 36-17.  This was followed by the Ravens trying their hand at coming back when Flacco found Crockett Gillmore on a 1-yard TD pass (with a failed 2-point conversion) for a 36-23 score.  But the Steelers were able to seal the game when Roethlisberger found Matt Spaeth on a 33-yard TD pass for a final score of 43-23. A week after passing for a franchise-record six touchdowns against Indianapolis, Roethlisberger duplicated the feat to lead Pittsburgh to its third consecutive win. The 12 touchdown passes over the last two games broke the NFL record of 11 set by Tom Flores for Oakland in the AFL in 1963 and matched by New England's Tom Brady in 2007.
Question: How many points were the Steelers leading by at the end of the first half?
Answer: 12