Year	Number of
1990	91.76
1991	91.97
1992	92.23
1993	93.65
1994	95.83
1995	97.34
1996	99.03
1997	101.45
1998	96.54
1999	97.07
2000	95.14
2001	92.11
2002	91.07
2003	89.43
2004	88.41
2005	88.35
2006	86.84
2007	83.41
2008	81.99
2009	82.19
2010	82.82
2011	84.34
2012	84.53
2013	85.49
2014	84.85
2015	83.82
2016	84.68