The Boston Fenway had the largest population shift of all Downtown Boston neighborhoods with an increase of 15 percent, followed by the Boston South End with a 12 percent jump, according to the census data complied by the BRA.
According to the BRA (which seems to contradict U.S. government data), Beacon Hill’s population shrank less than 1% when 109 housing units (apartments) were converted to single-family homes.
Based on BRA data, Back Bay grew 1%. Once again, this seems to contradict the federal government’s numbers, which had Back Bay growing at a faster pace.
The Boston Fenwway area added almost 1,300 housing units- apartments/condos, which helped in the Fenway population growth of 4, 500 new residents to the area.
Source: Boston Courant (Sorry no link)