Year	Number of
1990	193.56
1991	204.31
1992	215.03
1993	226.12
1994	238.35
1995	252.23
1996	261.49
1997	271.21
1998	280.55
1999	290.55
2000	301.39
2001	315.52
2002	329.69
2003	344.43
2004	359.61
2005	375.64
2006	392.5
2007	408.79
2008	425.96
2009	443.04
2010	460.19
2011	479.34
2012	497.61
2013	515.71
2014	532.34
2015	547.96
2016	570.36