New York City Mayor Bill De Blasio is calling for a rent freeze on the city's one million rent-controlled apartments, but is still raising the rent on several of his own properties.

The mayor and his family raised the rent of a two-family unit to $2,850 last year, which has increased in $50 and $75 increments from the $2,400 price in 2009. De Blasio also raised rent by $25 for another one of his properties in June 2015, according to documents obtained by Politico.

The de Blasios additionally charged $4,500 in rent for their former home when they moved into the official mayor's residence, Gracie Mansion, in 2014.

Although he continues to raise the rents of his own properties, de Blasio has advocated for the city's Rent Guidelines Board to freeze rent rates elsewhere. The board has ruled against increasing rates for rent-controlled units for two years.

But the mayor is allowed to increase rents on his properties because they were not included in the city's rent-stabilization program. A former City Hall spokesman explained that the mayor raised rates after making improvements to the apartment units.

The Rent Guidelines Board released a report showing that landlord costs have increased 6.2 percent this year while total income increased by 4.4 percent. Landlord costs include maintenance and insurance costs, fuel, labor, and property taxes.

A member of the board said the report justifies the board's decision to freeze rates again next year.

"If you look at owners' net operating income and overall gross rent roll, owners continue to do well even with the last two years of one-year rent freezes," board member Harvey Epstein said.

Back in March, De Blasio touted his work in freezing rates.