Year	Number of
1990	85.68
1991	89.26
1992	93.2
1993	97.59
1994	102.41
1995	107.64
1996	113.36
1997	119.64
1998	125.59
1999	127.76
2000	130.78
2001	134.52
2002	137.82
2003	142.23
2004	146.32
2005	151.18
2006	156.36
2007	162.12
2008	167.38
2009	174.67
2010	180.68
2011	186.49
2012	192.98
2013	199.68
2014	206.95
2015	214.46
2016	221.94