I want to know the answer to the following question:
Over approximately what expanse of time can textual criticism be applied to written works?
All the background I'm provided with is that "In the English language, the works of Shakespeare have been a particularly fertile ground for textual criticism—both because the texts, as transmitted, contain a considerable amount of variation, and because the effort and expense of producing superior editions of his works have always been widely viewed as worthwhile.". Is that enough to answer the question?
Answer: no