The unemployment rate dropped to 8.9 percent from 9 percent as nonfarm payrolls rose by 192,000 in February, the Labor Dept. reported Friday. That’s slightly better than the rise to 9.1 percent unemployment economists forecast, and the first time in two years that unemployment has fallen below 9 percent. Job growth in January was better than previously thought, adding 63,000 jobs instead of the previously estimated 36,000. Building and construction made gains in February, while government employment fell. Despite the gains, the Fed still expects unemployment to hover around 7.5 to 8 percent at the end of 2012.