By CHRISTOPHER S. RUGABERWASHINGTON (AP) â¿¿ Unemployment rates fell in less than half of U.S. states last month, as steady but slow hiring is making only gradual improvement in the job market. The Labor Department said Friday that rates fell in 22 states in December and rose in 16. They were unchanged in 12. The department's monthly report also shows that steady hiring nationwide in the past two years has lowered the unemployment rate in many parts of the country. The rate is now below 7 percent in 25 states. And some of the states hardest hit in the recession have seen solid gains. Nevada's unemployment rate, the highest in the nation, plummeted 0.6 percentage points last month to 10.2 percent. Rhode Island's rate, also 10.2 percent, fell from 10.4 percent in November. A year ago, Nevada reported an unemployment rate of 13 percent. Its 2.8 percentage point drop in 2012 was the biggest in the nation. Much of that decline stems from a smaller labor force. Many of those in Nevada who were out of work have given up looking for jobs or have left the state. People are only counted as unemployed if they are actively looking for work. Nevada's workforce fell nearly 2 percent last year. But some of the unemployed have found jobs. In the past year, the state has gained nearly 20,000 jobs. California has the third-highest unemployment rate, at 9.8 percent, the same as the previous month but down from 11.2 percent a year ago. Nationwide, the rate remained at 7.8 percent in December. Employers added 155,000 jobs last month, nearly matching the average of 153,000 in 2012 and 2011. That's just enough to slowly reduce the unemployment rate, which declined 0.7 percentage points nationwide last year. Employers added jobs in 27 states, the department said, while they cut jobs in 23 states. The job totals come from a survey of employers, while the unemployment rate is calculated from a separate survey of households.