Year	Number
1995	29.51136
1996	29.07044
1997	29.28452
1998	28.78043
1999	28.81621
2000	29.40376
2001	29.59608
2002	30.13601
2003	30.02794
2004	30.19933
2005	30.52918
2006	30.77352
2007	29.05982
2008	30.5171
2009	30.34313
2010	29.2597
2011	29.4472
2012	30.64097
2013	30.43715
2014	29.83592
2015	30.38387
2016	30.33873
2017	33.04179
2018	30.39653