The answer to this question would vary quite a bit country, e.g. looking at the second source below, a study has estimated that in 1500, the figure was about 55% in the Netherlands, but 75% in Poland and France, so the scope you've mentioned is very broad.
However, I did find a couple of sources: first off, the World bank has some data on fairly recent times, e.g. for the US from 1980 to 2010. In this source, it would probably be most interesting to look at rapidly developing countries such as India, Malaysia, or even China, although the Chinese figures seem quite odd, with a drop from 44.1% in 2002 to 4.4% in 2003 almost certainly signifying a major change in what was being measured, or outright fraud in one or both figures.
I also found a perhaps more user-friendly overview of some different studies at https://ourworldindata.org/agricultural-employment/. There are graphs at least for a sample of European countries from 1300-1400 onwards, and for the US from 1800-2000.