Year	Number
1995	15.73454
1998	16.54433
1999	16.3055
2000	15.54728
2001	15.07243
2002	13.8669
2003	14.98205
2004	14.88184
2005	12.89028
2006	12.89028
2007	13.66232
2008	12.49976
2009	13.04604
2010	12.8904
2011	14.25725
2012	16.05338
2013	14.39243
2014	14.7087
2016	13.89552
2017	15.19375
2018	15.41893