Year	Number of
1990	106.94
1991	98.78
1992	90.17
1993	80.71
1994	73.72
1995	68.44
1996	64.1
1997	62.24
1998	60.28
1999	59.91
2000	60.1
2001	61.17
2002	62.72
2003	65.07
2004	67.77
2005	71.05
2006	72.16
2007	73.9
2008	75.75
2009	77.29
2010	78.97
2011	80.17
2012	81.8
2013	83.54
2014	85.84
2015	88.55
2016	91.98