A percentile is the percentage of values in a dataset that fall below a particular value. For example, if your score on a test is in the 90th percentile, it means you scored higher than 90% of the people who took the test.

Formula:

Percentile = (Number of values below x / Total number of values) * 100

Therefore it can only be calculated if one has the entire data, thus only the officials know what exactly will be the best percentile.