Year	Number of
1990	84.85
1991	84.42
1992	85.93
1993	88.14
1994	87.81
1995	89.05
1996	87.09
1997	85.81
1998	85.01
1999	84.67
2000	88.44
2001	89.68
2002	91.56
2003	94.64
2004	95.65
2005	95.88
2006	96.63
2007	96.75
2008	95.04
2009	94.27
2010	95.45
2011	99.04
2012	103.69
2013	109.7
2014	115.49
2015	120.08
2016	124.51