The 1st Battalion, 24th Infantry Regiment deployed again under 1/25 SBCT to Afghanistan in support of Operation Enduring Freedom in 2011-2012. The battalion assumed responsibility for the Zabul Province, with assistance from Romanian units along Highway 1. The battalion HQ was primarily stationed at FOB Lagman in Zabul Province with companies co-located and dispersed north and south. 1-24 Infantry found themselves in a direct combat role again, losing several soldiers to Taliban attacks throughout their yearlong deployment, including an "insider attack" in Qalat on 8 January 2012.
Question: How many years did Operation Enduring Freedom last?
Answer: 2