The only exception is the specially governed district of Bangkok, whose governor is elected by its population, thus making him or her equivalent to a mayor. In the United States, the title "Governor" refers to the chief executive of each state or insular territory. Governors retain sovereign police power, are not subordinate to the federal authorities except by laws provided by the enumerated powers section of the federal constitution, and serve as the political and ceremonial head of the state. Nearly three-fourths of the states (36) hold gubernatorial elections in the same years as midterm elections (2 years off set from presidential elections). Eleven states hold them in the same years as presidential elections (Vermont and New Hampshire hold elections every two years in every even numbered year), while the remaining five hold them in odd numbered years (two in the year after a presidential election, three in the year before). In colonial North America, governors were chosen in a variety of ways, depending on how the colony was organized. In the crown colonies of Great Britain, France, and Spain, the governor was chosen by the ruling monarch of the colonizing power, or his designees; in British colonies, the Board of Trade was often the primary decision maker. Colonies based on a corporate charter, such as the Connecticut Colony and the Massachusetts Bay Colony, elected their own governors based on rules spelled out in the charter or other colonial legislation. In proprietary colonies, such as the Province of Carolina before it became a crown colony (and was divided into North and South), governors were chosen by the Lords Proprietor who controlled the colony. In the early years of the American Revolutionary War, eleven of the Thirteen Colonies evicted (with varying levels of violence) royal and proprietary governors. The other two colonies (Connecticut and Rhode Island) had corporate charters; Connecticut Governor Jonathan Trumbull was governor before and during the war period, while in Rhode Island, Governor Joseph Wanton was removed from office in 1775 for failing to support the rebel war effort. Before achieving statehood, many of the fifty states were territories. Administered by the federal government, they had governors who were appointed by the President and confirmed by the Senate rather than elected by the resident population. In Mexico, "governor" refers to the elected chief and head of each of the nation's thirty one Free and Sovereign States with the official Spanish title being "Gobernador". Mexican governors are directly elected by the citizens of each state for a six-year term and cannot be re-elected.