Philadelphia’s population grew slightly in 2018 for a 12th straight year of growth, according to Census Bureau estimates to be released Thursday, a streak that follows more than 30 years of mostly unbroken population losses that started in the 1970s.

Benjamin Gruswitz, senior planner at the Delaware Valley Regional Planning Commission, attributed the upward trend to several factors. In addition to an increase in the immigrant population and births outpacing deaths, he cited “an influx of people who want to live in higher-density places with walkable neighborhoods, short commutes to work, and access to transit and other amenities.”

The city added more than 3,900 residents between 2017 and 2018, about the same as in the previous yearlong period. Philadelphia’s population — which peaked at more than 2 million in 1950 — is now 1.58 million.

Philadelphia's Growth Trends

The city reached a population peak of over 2 million in 1950, then proceeded to lose over a half-million residents over the next 56 years …

… but, starting in 2006, Philadelphia started to gain in population again, and in 2018 posted its 12th straight year of growth.

Change in population from the previous year

SOURCE: U.S. Census Bureau

Nationwide, the counties with the highest numbers of new residents are in the South and the West. Of the country’s more than 3,100 counties, 55 percent gained residents between 2017 and 2018 and 44 percent lost residents. The populations of a dozen counties did not change.

Change in County Population, 2017 to 2018

Most of the counties with the highest rates of growth were concentrated in the West and South. Maricopa County in Arizona, home to Phoenix, topped all counties in numeric growth, adding over 81,000 new residents in one year.

SOURCE: U.S. Census Bureau