Year	total route-km
1980	458647.9
1981	458404.9
1982	460357.9
1983	461624.9
1984	462113.4
1985	466108.7
1986	466327.2
1987	466412.85
1988	467208.42
1989	471065.77
1990	477477.018483871
1991	478326.855483871
1992	480080.455483871
1993	478443.615483871
1994	479541.415483871
1995	478810.605483871
1996	481720.597589134
1997	486209.145483871
1998	483345.445483871
1999	483073.775483871
2000	489527.935483871
2001	486003.935483871
2002	489228.935483871
2003	487473.935483871
2004	488367.935483871
2005	517990.935483871
2006	518994.935483871
2007	522600.935483871
2008	520278.935483871
2009	512277.935483871
2010	514709.935483871
2011	516307.935483871
2012	515635.935483871
2013	515443.375483871
2014	520203.935483871
2015	520643.755483871
2016	521164.085483871