Estimating probability of an occurrence from historical data

I have 183 percentages based on the accuracy of a price prediction. (If I predict something will sell at 100, and it sells at 100, then I have sold at 100% of the prediction.) 16 times, the percentage was < 85%. I would like to know how to determine the probability of 100% of the percentages from another similar population would be < 85%. In other words, what is the likelihood that the next group of assets I buy (chosen from the same population) would ALL be under 85% actual price / target price?