【The rank of Professor is held by 29.5% of US academics，　NOT by US　postsecondary teachers。你应该是认得英文的，怎不知道这两者是不同的呢？】

“The rank of Professor is held by 29.5% of US academics”
here, academics means:

One who is a member of an institution of higher learning.

or

= postsecondary teachers

算术英文你要好好补补刻。我英文不灵，至少小学算术还行。