Year	Number of
1990	213.42
1991	217.85
1992	212.12
1993	211.35
1994	207.39
1995	206.41
1996	203.17
1997	203.61
1998	205.23
1999	203.24
2000	198.56
2001	193.15
2002	187.39
2003	187.8
2004	186.23
2005	186.2
2006	181.42
2007	184.63
2008	182.1
2009	180.75
2010	181.14
2011	180.58
2012	181.44
2013	178.85
2014	173.01
2015	177.71
2016	182.49