Year	Number of
1990	143.36
1991	146.75
1992	151.67
1993	159.22
1994	160.16
1995	165.68
1996	170.24
1997	177.61
1998	183.15
1999	182.26
2000	184.87
2001	184.25
2002	189.3
2003	192.2
2004	194.62
2005	193.01
2006	193.57
2007	195.36
2008	200.52
2009	207.31
2010	214.7
2011	219.22
2012	224.73
2013	231.01
2014	237.26
2015	244.06
2016	250.19