Year	Number of
1990	91.55
1991	95.36
1992	99.8
1993	103.55
1994	108.26
1995	113.55
1996	117.79
1997	121.96
1998	125.16
1999	128.79
2000	133
2001	138.61
2002	143.57
2003	149.59
2004	156.04
2005	162.87
2006	170.3
2007	178.29
2008	185.95
2009	194.49
2010	202.97
2011	208.45
2012	215.38
2013	219.29
2014	223.4
2015	228.68
2016	234.31