Article: The English language has been official in the state of Oklahoma since 2010. The variety of North American English spoken is called Oklahoma English, and this dialect is quite diverse with its uneven blending of features of North Midland, South Midland, and Southern dialects. In 2000, 2,977,187 Oklahomans—92.6% of the resident population five years or older—spoke only English at home, a decrease from 95% in 1990. 238,732 Oklahoma residents reported speaking a language other than English in the 2000 census, about 7.4% of the total population of the state. Spanish is the second most commonly spoken language in the state, with 141,060 speakers counted in 2000. The next most commonly spoken language is Cherokee, with about 22,000 speakers living within the Cherokee Nation tribal jurisdiction area of eastern Oklahoma. Cherokee is an official language in the Cherokee Nation tribal jurisdiction area and in the United Keetoowah Band of Cherokee Indians.

Question: When did Oklahoma declare an official language?
2010