Year Number per 1,000 adults 2007-01-01 294.00500000000000 2008-01-01 309.53600000000000 2009-01-01 460.95500000000000 2010-01-01 468.97900000000004 2011-01-01 500.60500000000000 2012-01-01 639.21900000000000 2013-01-01 645.33300000000010 2014-01-01 647.92400000000000 2015-01-01 661.89000000000000