Year	hours
2005	471.3421052631579
2006	473.775
2007	470.675
2008	382.185
2009	360.0571428571428
2010	337.4761904761905
2011	319.4761904761905
2012	277.3809523809524
2013	265.09090909090907
2014	254.1818181818182
2015	252.32954545454547
2016	240.5681818181818
2017	236.6590909090909
2018	231.9318181818182
2019	230.20454545454547
