New Jersey’s unemployment rate edged lower to 9.1 percent last month. However, a separate survey shows employers reduced their workforce in December.Employment in the Garden State was down by 16,300 jobs last month, reversing the more than 12,000 job gains in November.New Jersey Business and Industry Association President Phil Kirschner said Wednesday the month-to-month volatility is not a big surprise.”The up and down during the November-December time is not unusual historically. So, we’ll see what this next quarter brings,” he said. “January-February-March may bring us a better idea of what the job market looks like in the year ahead.”Most of the jobs losses in December were in the private sector. Eight of 10 industry groups showed employment declines. Kirschner said businesses in New Jersey are still predicting modest gains in hiring this year.