Year	Number
2004-01-01	6.8431
2005-01-01	9.4254
2006-01-01	11.3712
2007-01-01	13.8644
2008-01-01	17.6649
2009-01-01	21.0398
2010-01-01	23.3181
2011-01-01	25.9056
2012-01-01	28.1193
2013-01-01	30.5657
2014-01-01	32.9176
2015-01-01	29.6015
2016-01-01	31.8223
2017-01-01	33.4347