Year	Number of
1990	349.91
1991	348.4
1992	349.35
1993	352.78
1994	344.53
1995	340.72
1996	334.34
1997	343.47
1998	344.53
1999	341.8
2000	336.12
2001	332.14
2002	327.25
2003	326.34
2004	324.43
2005	317.54
2006	316.05
2007	313.57
2008	311.36
2009	309.34
2010	308.49
2011	303.8
2012	304.19
2013	305.86
2014	300.88
2015	314.46
2016	321.46