Year	Number
1994	13.73754
1995	13.55704
1996	13.75888
1997	14.49214
1998	15.11158
1999	15.17111
2000	16.39112
2001	18.79829
2002	18.73987
2003	16.74239
2004	17.37843
2005	17.66761
2006	17.74771
2007	16.37739
2008	16.18714
2009	16.27126
2010	16.16547
2011	16.91018
2012	16.80229
2013	18.45888
2014	17.83837
2015	16.88879
2016	16.19484
2017	15.95609
2018	15.74672