Year	Number
1995	18.89847
1996	21.40469
1997	14.37392
1998	15.78078
1999	19.13064
2000	20.16725
2001	21.51285
2002	22.62608
2003	22.39489
2004	24.17749
2005	23.0992
2006	20.72839
2007	21.08535