Year	Number
2008-01-01	15.6028
2009-01-01	17.5439
2010-01-01	19.8582
2011-01-01	22.0885
2012-01-01	23.2643
2013-01-01	29.1153
2014-01-01	31.7936
2015-01-01	33.4173
2016-01-01	35.6850
2017-01-01	36.9634