Year	Number
1993	9.94527
1994	11.44878
1995	12.70882
1996	14.83875
1997	15.96188
1998	15.15663
1999	17.36598
2000	18.30474
2001	19.87888
2002	19.77292
2003	19.68322
2004	19.4397
2005	22.26185
2006	21.84506
2007	21.68305
2008	21.55204
2009	21.20523
2010	20.94328
2011	20.27201
2012	19.79362
2013	18.50407
2014	17.64113
2015	17.09531