The income for the Japanese has not increased in the past 30 years.
There is no merit for people to work in Japan, so the number of young people going abroad to work is increasing.
Japan is no longer one of the world economic powers.
ご質問ありがとうございます。
"The income for the Japanese has not increased in the past 30 years."＝「過去30年間、日本人の収入は増えていません。」
"There is no merit for people to work in Japan,"＝「日本で働くメリットは人々にありません」
"so the number of young people going abroad to work is increasing."＝「なので、海外で働きに行く若い人の数が増えています。」
"Japan is no longer one of the world economic powers."＝「日本は経済大国ではもうありません。」
ご参考までに。
アメリカ合衆国 
