Year	Number of
1990	27.13
1991	28.27
1992	29.55
1993	31.08
1994	32.8
1995	34.72
1996	37.42
1997	40.47
1998	43.94
1999	47.66
2000	51.63
2001	54.7
2002	57.68
2003	60.78
2004	64.1
2005	67.79
2006	68.6
2007	69.49
2008	70.95
2009	72.41
2010	73.87
2011	77.8
2012	81.92
2013	86.44
2014	91.17
2015	96.13
2016	102.13