Year Number 2008-01-01 276.9499 2009-01-01 211.1079 2010-01-01 168.9774 2011-01-01 181.6823 2012-01-01 209.7282 2013-01-01 217.8713 2014-01-01 260.8034 2015-01-01 247.3758 2016-01-01 281.2025 2017-01-01 309.9871