Year	Number of
1990	1219.13
1991	1229.46
1992	1243.82
1993	1253.58
1994	1256.26
1995	1260.69
1996	1271.93
1997	1270.6
1998	1258.06
1999	1253.65
2000	1242.1
2001	1237.61
2002	1254.64
2003	1267.59
2004	1257.63
2005	1260.5
2006	1255.33
2007	1249.22
2008	1246.14
2009	1243.76
2010	1228.61
2011	1244.88
2012	1255.07
2013	1262.8
2014	1262.45
2015	1290.6
2016	1317.56