Of the nearly 140 teacher strikes that occurred nationally between 2000 and 2007, 60 percent took place in Pennsylvania, according to a report released in August 2012, by the Allegheny Institute for Public Policy. Pennsylvania is one of 13 states in which teacher strikes are legal. In the Commonwealth of Pennsylvania, there were three teacher union strikes in 2010; one teacher union strike in 2011, one teacher union strike in 2012 and three teacher union strikes in 2013. Crestwood School District in Luzerne County went on strike in 2009. Neshaminy School District teachers union went on strike twice in 2012. Wyoming Area School District, Old Forge School District and Shaler Area School District went on strike in the fall of 2013. Wyoming Area School District and Danville Area School District teachers went on strike in the spring of 2014. In the fall of 2014, three Pennsylvania public school district teachers unions went on strike including: Millville Area SD, East Allegheny School District and Old Forge School District. In 2015, there were multiple strikes in Pennsylvania including: Line Mountain School District, Shamokin Area School District, Old Forge School District, Scranton School District.