1. RankingProject::TravelTime2011
    Mean travel times to work, from 2011 ACS.
  2. RankingProject::TravelTime2011.1dec
    Mean travel times to work, from 2011 ACS, rounded to 1 decimal place.
  3. surveyCV::NSFG_data
    Subset of the 2015-2017 National Survey of Family Growth (NSFG): one birth per respondent.
  4. surveyCV::NSFG_data_everypreg
    Subset of the 2015-2017 National Survey of Family Growth (NSFG): all live births per respondent.