Given the task definition and input, reply with output. This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.

According to heraldic sources total number of legal ennoblements issued between the 14th century and the mid-18th century, is estimated at approximately 800. This is an average of only about two ennoblements per year or only 0.000 000 14 – 0.000 001 of historical population. Compare: historical demography of Poland.
Around what time was the total legal number of ennoblement at 800?