Japan, recovering from the March 11 earthquake-tsunami disaster, Friday reported the September jobless rate dropped to 4.1 percent from 4.3 percent in August.The government said the jobless figures included data from the Iwate, Miyagi and Fukushima prefectures, which were hit the hardest by the quake devastation, Kyodo News reported.It was the second straight month of improvement in the jobless picture.However, the government said it remains concerned about the sharp appreciation of the yen against other major world currencies. A higher yen makes Japanese exports more expensive, thus adversely affecting the export-dependent Japanese economy.