Year	Number of
1990	88.37
1991	90.49
1992	92.6
1993	94.72
1994	97.02
1995	99.54
1996	101.39
1997	103.37
1998	105.53
1999	107.84
2000	110.38
2001	113.05
2002	115.97
2003	119.18
2004	122.58
2005	126.18
2006	131.41
2007	136.99
2008	142.92
2009	149.33
2010	156.31
2011	160.48
2012	165.01
2013	169.65
2014	174.43
2015	179.31
2016	184.47