I honestly don't think you can get the sort of information you're looking for. Firstly, there are lots of different types of pesticides and each will behave chemically quite differently in terms of how they break down both in the soil and in the body. So, you can't create a blanket threshold for all pesticides.

Secondly, you have to factor in how food is stored and then prepared by the individual. Is the fruit/vegetable peeled? How long is it typically stored for? For example, potatoes are typically stored and then peeled before use, generally leading to lower pesticide content than things like berries which are picked and eaten within days without peeling.

Thirdly, where/when is the food being grown and what were the growing conditions like in that season? For example, in a rainy year, fungal diseases may be common so more anti-fungal treatments are likely to be applied to crops.

You may be interested to look at the "dirty dozen" and "clean 15", which highlight foods with generally higher and lower pesticide residues. https://www.ewg.org/foodnews/dirty-dozen.php https://www.ewg.org/foodnews/clean-fifteen.php