Year	Number of
1990	68.24
1991	70.38
1992	71.69
1993	71.45
1994	73.42
1995	76.56
1996	77.05
1997	76.05
1998	77.54
1999	77.02
2000	78.84
2001	84.67
2002	85.54
2003	88.9
2004	89.38
2005	89.62
2006	91.95
2007	94.74
2008	99.42
2009	100.63
2010	101.96
2011	102.42
2012	104.36
2013	109.34
2014	113.49
2015	114.68
2016	117.67