Fewer Americans sought unemployment aid last week, reducing the average number of weekly applications last month to a five-year low. The drop shows that fewer layoffs are strengthening the job market. The Labor Department says applications fell 10,000 to a seasonally adjusted 332,000. That pushed the four-week average to 346,750, the lowest since March 2008, just several months after the Great Recession began. Applications are a proxy for layoffs. They have fallen nearly 13 percent since November.