Year	Number of
1990	98.85
1991	97.75
1992	97.98
1993	96.91
1994	98.05
1995	100.34
1996	101.48
1997	100.12
1998	100.21
1999	103.68
2000	108.37
2001	112.36
2002	116.23
2003	120.12
2004	125.23
2005	129.63
2006	134.18
2007	138.7
2008	144.35
2009	151.65
2010	158.01
2011	163.48
2012	169
2013	174.09
2014	178.27
2015	182.91
2016	188.05