Year	Number
1996	6.38297891616821
1998	15.957447052002
2000	8.99470901489258
2002	10.582010269165
2003	5.52763795852661
2004	7.76699018478394
2005	9.22330093383789
2006	13.043478012085
2007	13.043478012085
2008	11.5384616851807
2009	7.5829381942749
2010	9.95260620117188
2011	13.7440757751465
2012	11.3744077682495
2013	13.2701425552368
2014	17.1428565979004
2015	21.9047622680664
2016	25.238094329834
2017	25.238094329834
2018	24.5283012390137
2019	25.943395614624
2020	20.2830181121826
2021	20.2830181121826
2022	16.9811325073242