Year	total route-km
1980	70564.7
1981	70806.7
1982	71215.7
1983	72257.7
1984	72257.7
1985	72823.7
1986	73184.7
1987	73480.7
1988	73726.7
1989	74056.7
1990	74531.635483871
1991	73103.635483871
1992	73262.635483871
1993	73498.635483871
1994	73737.635483871
1995	74509.635483871
1996	75893.635483871
1997	77624.635483871
1998	77668.935483871
1999	78007.935483871
2000	78774.935483871
2001	79152.935483871
2002	79318.935483871
2003	80372.935483871
2004	80889.935483871
2005	82182.935483871
2006	83404.935483871
2007	83629.935483871
2008	81172.935483871
2009	85534.935483871
2010	86282.935483871
2011	86677.935483871
2012	87188.935483871
2013	87188.935483871
2014	87879.935483871
2015	88933.935483871
2016	87974.935483871