Following a terrible loss to the Browns, the Steelers returned home for a duel against the Texans on Monday Night Football.  The Texans started out strong when Ryan Fitzpatrick found Alfred Blue on an 11-yard pass for a 7-0 lead and the only score of the first quarter.  In the 2nd quarter, the Texans increased their lead as Randy Bullock nailed 2 field goals from 39 and 38 yards out for 10-0 and 13-0 leads.  The Steelers finally got on the board and scored 24 unanswered points:  first starting with Shaun Suisham who nailed a 44-yard field goal for a 13-3 game followed up by Ben Roethlisberger finding Martavis Bryant on a 35-yard TD pass for a 13-10 game and eventually took the lead on Antonio Brown's 1-yard TD pass to Lance Moore 17-13 and lastly Roethlisberger hooking up with Le'Veon Bell on a 2-yard TD pass for a 24-13 halftime lead.  After a scoreless 3rd quarter, the Texans came within 8 as Bullock kicked a 31-yard field goal for a 24-16 game not long before the Steelers responded with 2 of their own from Suisham when he got them from 30 and 40 yards out for leads of 27-16 and 30-16.  Finally, Fitzpatrick was able to find Arian Foster on a 1-yard TD pass and this led to the final score of 30-23.

Based on the above article, answer a question. How many points were the Steelers leading by at the end of the first half?
11