Year	total route-km
1980	143419.7
1981	143488.7
1982	143787.7
1983	143840.7
1984	144467.2
1985	145782.5
1986	145229.5
1987	145481.15
1988	145587.72
1989	145759.07
1990	145080.655483871
1991	148204.155483871
1992	147590.155483871
1993	146990.515483871
1994	147760.515483871
1995	148343.605483871
1996	143919.735483871
1997	147650.145483871
1998	144995.445483871
1999	144394.275483871
2000	148231.935483871
2001	144874.935483871
2002	148420.935483871
2003	148623.935483871
2004	149250.935483871
2005	148775.935483871
2006	149083.935483871
2007	148951.935483871
2008	147795.935483871
2009	147380.935483871
2010	148104.935483871
2011	148319.935483871
2012	147836.935483871
2013	147836.435483871
2014	150748.935483871
2015	151117.165483871
2016	150971.935483871