Year	Number
1994	14.4925
1996	17.40847
1997	17.92587
1998	20.38234
1999	17.83026
2000	18.00825
2001	16.84625
2002	17.51824
2003	17.31311
2004	15.73277
2005	15.34251
2006	15.16564
2007	14.78004
2008	14.8028
2009	14.98009
2010	14.84854
2011	14.85061
2012	14.8457
2014	14.69977
2015	14.74387
2016	14.83472
2017	15.01533