Year	Number
1994	16.57055
1995	17.40872
1996	17.97591
1997	18.31973
1998	18.38368
1999	18.31838
2000	18.53145
2001	19.085
2002	18.94107
2003	19.70664
2004	19.22661
2005	18.40763
2006	17.5299
2007	17.08633
2008	16.44069
2009	16.21414
2010	15.76055
2011	15.6437
2012	15.41624
2013	14.89915
2014	14.50294
2015	14.29692
2016	14.01001
2017	14.2981
2018	14.36246