If we consider the data items of 25 numbers and say for some reason we are only interested in the top 1% of the values or in other words we say 99 percentile how we would we apply the formula

L§= p(n+1)/100

L(90)=90/100 (*26)= 25.74

Since there are 25 values how do we calculate?

Also we hear the term people saying that they have scored 100 percentile. Which value would it correspond to?