"According to metrics used to complete the index, an average Wilmington family pays $3,969 a year in combined property taxes and utility services."

Regardless of how hard you search, you can't find the actual survey, just his opinion about the survey. Teasing out water, sewer, and the remaining metrics used (and the ones omitted) would give us a more realistic portrait of "stewardship," until that time, we don't really know how he measured what.