Year	Number of
1990	118.78
1991	123.74
1992	122.62
1993	127.71
1994	130.15
1995	127.09
1996	123.78
1997	125.87
1998	127.36
1999	127.88
2000	134.69
2001	138.15
2002	136.87
2003	139.45
2004	140.61
2005	145.18
2006	144.75
2007	143.69
2008	140.8
2009	138.52
2010	132.41
2011	140.28
2012	145.66
2013	151.92
2014	154.21
2015	153.88
2016	155.43