Year	Number of
1990	262.54
1991	242.48
1992	221.76
1993	196.42
1994	187.79
1995	174.57
1996	162.59
1997	153.35
1998	145.33
1999	141.2
2000	138.2
2001	140.58
2002	143.82
2003	147.57
2004	151.32
2005	154.82
2006	155.58
2007	156.37
2008	158.67
2009	163.05
2010	170.69
2011	179.1
2012	178.12
2013	177.57
2014	182.02
2015	188.06
2016	193.29