Indeed, nearly 98% of countries ranked AAA were either at that rating, or the AA level, 15 years later.

实际上，十五年过后，原先国债被评为AAA级国家要么还是这个级别，要么就是AA级。

youdao

Currently, 80 percent of the bonds issued in China are backed by State credit and most of the rest come from large companies that have AAA or AA ratings.

FORBES: China In Transition