Year	total route-km
1980	74384
1981	74374
1982	74544
1983	74619
1984	75027
1985	74965
1986	74868
1987	74948.65
1988	74958.52
1989	75184.87
1990	75340.52
1991	75440.52
1992	75497.52
1993	75433.88
1994	75432.88
1995	75631.97
1996	74713.1
1997	74740.51
1998	75521.51
1999	74765.34
2000	74765
2001	75034
2002	75143
2003	75215
2004	75295
2005	75560
2006	75427
2007	75422
2008	75416
2009	75362
2010	76063
2011	76549
2012	76549
2013	76549
2014	77897
2015	79583
2016	79583