ANNAPOLIS -- Maryland residents face a 4-cent increase in a gallon of gasoline come July, the latest in a succession of 32 new and increased taxes and fees that Gov. Martin O'Malley has imposed since he took office in 2007.

The most recent of the $2.3 billion in higher taxes came last year, when O'Malley signed off an increase on income taxes for residents earning at least $100,000. That is expected to bring in about $144 million a year.

But that's not the only income tax approved during O'Malley's administration, according to conservative group Change Maryland. O'Malley's administration encompassed the recession where nearly every state saw dramatic declines in revenue.

During a special session in fall 2007, new income tax brackets and rates were established, increasing rates to between 4.75 percent and 5.5 percent. The next year a so-called "millionaires tax" raised the top rates to 6.25 percent, though that surcharge expired in 2010.

The biggest earner for the state was the Maryland state sales tax's jump from 5 percent to 6 percent, also enacted by the legislature during 2007's special session. That raised $613 million a year for the state coffers.

During the 2007 special session, the corporate income tax was also increased from 7 percent to 8.25 percent.

In 2011, the sales tax on alcoholic beverages was increased from 6 percent to 9 percent, bringing in about $85 million. Also in 2011, the fees for vanity plates and birth certificates were doubled from $25 to $50 and from $12 to $24, respectively.

Also in 2011, tolls were raised on Maryland's roads and bridges, including a 60 percent increase in tolls on the Chesapeake Bay Bridge.

In 2007, the tax on cigarettes was doubled from $1 to $2 per pack.

O'Malley's office did not respond to a request for comment.