Year	hours
2005	334.94642857142856
2006	336.19736842105266
2007	332.39473684210526
2008	310.58728070175437
2009	295.01260869565215
2010	290.15913043478264
2011	287.17826086956524
2012	284.41101694915255
2013	304.3118650793651
2014	299.3753571428571
2015	296.7860714285714
2016	280.53011904761905
2017	275.21464285714285
2018	271.67297619047616
2019	266.7598809523809