how many railway lines go through the station maintained by public transport authority ?
SELECT DISTINCT COUNT attr_open var_uri attr_close where brack_open var_x dbo_owningOrganisation dbr_Public_Transport_Authority_ attr_open Western_Australia attr_close sep_dot var_x dbo_servingRailwayLine var_uri sep_dot var_uri a dbo_RailwayLine brack_close