Year	Number of
1990	192.28
1991	199.08
1992	206.78
1993	215.25
1994	224.39
1995	234.37
1996	237.21
1997	240.79
1998	244.85
1999	249.39
2000	254.59
2001	256.15
2002	258.49
2003	261.36
2004	264.72
2005	268.77
2006	273.8
2007	279.21
2008	285.5
2009	292.36
2010	299.95
2011	308.16
2012	317.24
2013	326.94
2014	337.19
2015	347.98
2016	358.31