Washington state’s minimum wage will increase to $9.19 an hour starting Jan. 1, the Department of Labor & Industries said Friday.

The 15-cent increase from $9.04 an hour is based on a 1.67 percent increase in the Consumer Price Index for urban wage earners and clerical workers, as required by Initiative 688, which voters passed in 1998. Most of the increase in the index, which measures average price changes for goods and services, was the result of gas prices rising.

The state minimum wage applies to farm and nonfarm jobs; 14- and 15-year olds can be paid 85 percent of the adult minimum wage, officials said.

Since 2008, the state minimum wage has risen 14 percent. Washington is one of 10 states that peg their minimum wage to inflation.

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While Washington has the highest minimum wage among the states, it isn’t the highest in the country. San Francisco, which also indexes its minimum wage to local inflation, has that distinction. The city’s minimum wage this year is $10.24.