Trend 2009 - 2012. China Data Center, University of Michigan. China Yearly Statistics (National/Provincial/City/County): Transport | Country: China | All Provinces: Henan | Cities: Jiyuan City | GroupCode: 170203.b0201 | Labor Metric*: Length of Highways - Period end value, 2009-2012. Data-Planet™ Statistical Ready Reference by Conquest Systems, Inc. Dataset-ID: 035-002-013.