Year	Number of
1990	121.46
1991	122.46
1992	122.91
1993	124.81
1994	127.04
1995	127.66
1996	127.61
1997	127.52
1998	127.68
1999	129.47
2000	130.5
2001	131.91
2002	133.07
2003	135.67
2004	138.46
2005	141.48
2006	144.87
2007	147.93
2008	151.81
2009	155.9
2010	160.38
2011	165.02
2012	169.92
2013	174.55
2014	179.52
2015	184.91
2016	190.54