Year Number 2004-01-01 1685 2005-01-01 2790 2006-01-01 4447 2007-01-01 5730 2008-01-01 6720 2009-01-01 6742 2010-01-01 5851 2011-01-01 5798 2012-01-01 5824 2013-01-01 5790 2014-01-01 5441 2015-01-01 5609 2016-01-01 6574 2017-01-01 7012