Year	hours
2005	331.83720930232556
2006	326.8863636363636
2007	320.9318181818182
2008	311.97727272727275
2009	306.04545454545456
2010	307.7568181818182
2011	310.39772727272725
2012	308.64444444444445
2013	309.50902173913045
2014	307.03076086956526
2015	305.28076086956526
2016	289.24815217391307
2017	285.0296739130435
2018	284.7209782608696
2019	284.80141304347825