Year	Number of
1990	92.18
1991	95.38
1992	98.72
1993	102.27
1994	106.04
1995	110.08
1996	113.65
1997	117.41
1998	121.29
1999	125.32
2000	129.58
2001	133.14
2002	136.8
2003	140.82
2004	145.25
2005	150.23
2006	155.52
2007	161.23
2008	167.89
2009	174.91
2010	182.25
2011	190.27
2012	198.59
2013	207.11
2014	216.25
2015	226.17
2016	237.67