Top 5 values from a list of values

Hello,
Can some one help me to find top 5 values from a list.
I am trying to make small model for analysing production data, I have the required data in a sheet which contains data for different months and production activities like production, scrap,machinetype, downtime etc.
I have made the Model which has come out good in the sense its quite flexible for an user to select Month/location/machinetype from a dropdown which helps to analyse data like efficiency etc.
I want to pick up top five reasons ( I have some 15 types of Downtime) for machine downtime. is it posible to do so.
Thanks in advance
Vijay