Year	Number
1994	13.65662
1995	13.47371
1996	13.68216
1997	14.43766
1998	15.07997
1999	15.14201
2000	16.39929
2001	18.89492
2002	18.82948
2003	16.76009
2004	17.41199
2005	17.70709
2006	17.7866
2007	16.38278
2008	16.18829
2009	16.26159
2010	16.16581
2011	16.92511
2012	16.81494
2013	18.50587
2014	17.87186
2015	16.90308
2016	16.1968
2017	15.95431
2018	15.74733