The first thing I would see in this is more cars being registered out of state.
Maine's gas tax is in the middle of all gas taxes by state at $ .30 per gallon. I cannot find a breakdown on the fuel tax (Aeronautical fuel tax was listed separately in the report I finally found) on the state's website, but the total budgeted for the fiscal year is $224,703,184 million. The state has 1,330,399 registered vehicles but they are in diverse categories so not all registrants pay the same amount.
Steven Scharf
PS: in my research, I found out that The District of Columbia has the highest Jet Fuel tax. They have no airports in DC.