Japan’s unemployment rate improved to 4.4 percent in May amid a gradual recovery from the earthquake, tsunami and nuclear disasters of a year ago. The government’s Ministry of Internal Affairs and Communications released data Friday that showed jobless people totaled 2.97 million people in May, 170,000 fewer than the same month the previous year, to record on-year declines for two years straight. The 4.4 percent unemployment rate declined 0.2 percentage points from April. Manufacturing, transportation, medical and welfare sectors all gained