how many railway lines go through the station maintained by norwegian state railways ?
SELECT DISTINCT COUNT attr_open var_uri attr_close where brack_open var_x dbo_owningOrganisation dbr_Norwegian_State_Railways_ attr_open 1883–1996 attr_close sep_dot var_x dbo_servingRailwayLine var_uri sep_dot var_uri a dbo_RailwayLine brack_close