Year	Number
1996	33.5
1998	32.8358192443848
2000	30.8457717895508
2002	29.3532333374023
2003	25.3731346130371
2004	21.634614944458
2005	18.269229888916
2006	13.942307472229
2007	11.057692527771
2008	12.5
2009	13.7440757751465
2010	13.7440757751465
2011	14.0845069885254
2012	15.4929580688477
2013	15.023473739624
2014	16.7487678527832
2015	18.2266006469727
2016	15.7635469436646
2017	15.2709360122681
2018	13.1067962646484
2019	14.4927539825439
2020	15.4589376449585
2021	14.9758453369141
2022	14.0096616744995