Year	Number
1996	33.5
1998	33.3333320617676
2000	30.8457717895508
2002	30.348258972168
2003	26.8656711578369
2004	30.769229888916
2005	28.8461532592773
2006	34.1346168518066
2007	35.5769233703613
2008	34.1346168518066
2009	33.6492881774902
2010	32.7014236450195
2011	30.9859161376953
2012	30.046947479248
2013	29.577465057373
2014	30.5418720245361
2015	29.0640392303467
2016	32.019702911377
2017	32.019702911377
2018	30.5825233459473
2019	30.917875289917
2020	31.4009666442871
2021	29.9516906738281
2022	28.019323348999