Harvard student Lamont has the data, now he needs a thesis:

This morning I conducted some more test runs on the Xinhua data from
the 1980s and 1990s. It seems there are enough references to certain
other terms for me to build a more solid analysis.
Interesting
trends appear when I did a count of the frequency of references to
"Taiwan" in Xinhua stories. In the early 1980s, there were only a few
hundred refs per year, but this spiked in the late 1980s (corresponding
with the re-opening of personal contacts between the two sides) and mid
to late 1990s. By 1999, about 2000 stories per year mentioned Taiwan in
the lead paragraph. This could warrant further study.

I await the conclusion.