Definition: Rewrite each original sentence in order to make it easier to understand by non-native speakers of English. You can do so by replacing complex words with simpler synonyms (i.e. paraphrasing), deleting unimportant information (i.e. compression), and/or splitting a long complex sentence into several simpler ones. The final simplified sentences need to be grammatical, fluent, and retain the main ideas of their original counterparts without altering their meanings.
Input: Since then, documentation of saffron's use over the span of 4,000 years in the treatment of some 90 illnesses has been uncovered.

Since then, we have seen proof of saffron treating some 90 illnesses over 4,000 years.