Year	total route-km
1980	532893.435483871
1981	528645.387096774
1982	525485.1
1983	521374.941935484
1984	512108.064516129
1985	500356.925806452
1986	488495.938709677
1987	474676.664516129
1988	466529.470967742
1989	460013.54516129
1990	493413.364516129
1991	489588.851612903
1992	481477.887096774
1993	486790.838709677
1994	483559.335483871
1995	481644.35483871
1996	483265.177296862
1997	478063.32689211
1998	474887.47020934
1999	473497.721417069
2000	473224
2001	466648.297906602
2002	469869.703703704
2003	468812.00805153
2004	466476.00805153
2005	468149.00805153
2006	540279
2007	535382
2008	537159
2009	541261
2010	559555
2011	538238
2012	533259
2013	533970
2014	532151
2015	528799.79
2016	527831.56