national railway network
... that, out of the 2,600 km (1,600 mi) of track in use in Vietnam's national railway network, 85% of passenger volume and 60% of cargo volume is transported along the 1,726 km (1,072 mi) North–South Railway line?
... that, out of the <span about="#mwt81" data-mw='{"parts":[{"template":{"target":{"wt":"convert","href":"./Template:Convert"},"params":{"1":{"wt":"2600"},"2":{"wt":"km"},"abbr":{"wt":"on"}},"i":0}}]}' id="mwG20" typeof="mw:Transclusion">2,600</span><span about="#mwt81" typeof="mw:Entity"> </span><span about="#mwt81">km (1,600</span><span about="#mwt81" typeof="mw:Entity"> </span><span about="#mwt81">mi)</span> of track in use in <a href="./Vietnam" id="mwG24" rel="mw:WikiLink" title="Vietnam">Vietnam</a>'s <b id="mwG28"><a href="./List_of_railway_lines_in_Vietnam" id="mwG3A" rel="mw:WikiLink" title="List of railway lines in Vietnam">national railway network</a></b>, 85% of passenger volume and 60% of cargo volume is transported along the <span about="#mwt82" data-mw='{"parts":[{"template":{"target":{"wt":"convert","href":"./Template:Convert"},"params":{"1":{"wt":"1726"},"2":{"wt":"km"},"abbr":{"wt":"on"}},"i":0}}]}' id="mwG3E" typeof="mw:Transclusion">1,726</span><span about="#mwt82" typeof="mw:Entity"> </span><span about="#mwt82">km (1,072</span><span about="#mwt82" typeof="mw:Entity"> </span><span about="#mwt82">mi)</span> <a class="mw-redirect" href="./North-South_Railway,_Vietnam" id="mwG3I" rel="mw:WikiLink" title="North-South Railway, Vietnam">North–South Railway</a> line?