Year	Number of
1990	85.74
1991	86.39
1992	86.02
1993	84.6
1994	82.76
1995	80.79
1996	82.11
1997	83.41
1998	85.11
1999	87.15
2000	89.67
2001	94.94
2002	101.33
2003	108.97
2004	116.99
2005	125.23
2006	132.21
2007	138.58
2008	144.78
2009	151
2010	157.58
2011	164.24
2012	170.95
2013	177.45
2014	183.98
2015	190.65
2016	199.63