Complex sentence: As of the 2010 census, the population was 316,236, making it the third-most populous county in Virginia (behind Fairfax County and Prince William County, respectively), in July 2014, the population was estimated to be 330,043.
Split into simpler sentences: As of the 2010 census, the population was 316,236, making it the third-most populous county in Virginia (behind Fairfax County and Prince William County, respectively). In July 2014, the population was estimated to be 330,043.