Hawaii’s unemployment rate decreased in December to its lowest level ever.

The state’s seasonally adjusted jobless rate, which has been the lowest in the country, dropped to 2 percent last month while the November rate was revised upward to 2.1 percent, according to data released Monday by the state Department of Labor and Industrial Relations.

Nonfarm payroll jobs increased by 2,100 in December over the previous month with the educational and health services sector showing the largest gain at 1,000.

The labor force, which includes people who are employed, those who are unemployed but actively seeking work, and those who are self-­employed, fell last month to 682,200 from 684,400 in November as people continue to leave Hawaii to seek jobs on the mainland. The number of people employed fell to 668,600 from 670,350 the previous month while those unemployed fell to 13,550 from 14,050.

The unemployment rate fell in all four of the main counties. State and national labor-force data are adjusted for seasonal factors, but the county jobs data are not seasonally adjusted and thus do not take into account variations such as the winter holiday and summer vacation seasons.

Honolulu County’s rate declined to 1.7 percent from 1.9 percent, Hawaii County’s rate decreased to 2.0 percent from 2.4 percent, Kauai County’s rate fell to 1.7 percent from 2.0 percent and Maui County’s rate dropped to 1.8 percent from 2.1 percent. Within Maui County, Maui island’s rate fell to 1.7 percent from 2.1 percent, Molokai’s rate declined to 4.0 percent from 5.2 percent and Lanai’s rate decreased to 1.2 percent from 1.6 percent.