Montgomery County added more people than any other county in Maryland in the latest U.S. Census estimate, continuing a rate of population growth that put it over the 1 million mark in 2012.

According to new Census population estimates for July 1, 2012 to July 1, 2013, Montgomery County added 12,201 people, about 3,500 more than Prince George’s County, 6,800 more than Baltimore County and 7,000 more than Howard County added in the same period.

That puts Montgomery County’s total population at 1,016,677, making it the most populous county in Maryland.

From July 1, 2011 to July 1, 2012, the Census bureau estimated Montgomery County added about 13,000 people — a number which included about 8,700 people moving into the county. That put the total population over the 1 million mark.

Howard County had the fastest growth rate from 2012 to 2013, with a 1.7 percent population increase. Charles County followed with a 1.4 percent increase. Montgomery had a 1.2 percent growth rate, followed by 1 percent growth rates in both Anne Arundel and Prince George’s County.