Year	Number
1992	62.02681500499215
1993	60.52568493150685
1994	56.58161058731943
1995	49.02135871991704
1996	43.13642918600565
1997	33.21506030388488
1998	19.981153669125604
1999	17.151698730046824
2000	17.269631589592596
2001	17.30637574634618
2002	17.69356414860703
2003	16.465445462114907
2004	16.078978046827817
2005	15.44553484838406
2006	15.276418786692759
2007	14.04550088683435