When a year is interrupted by a word or two, the English rule says to write out the number
in words. That is always the fallback position. However, as always in reporting, numbers
written in words do not always serve us well.
Let's perhaps consider a new way to do it.
...during 19-, maybe, -98...
...after 19-, probably, -63...
I think this is easily readable and, at the same time, accurately reflects what was said.
The "2000" interruption is a bit more problematic. If we use only the first two digits, it doesn't really look like "2000."
Here is, then, a suggestion, though there may be others that work.
...during 2000-, maybe, -9...
...after 2000-, probably, -5...
Happy punctuating!
Margie