Top 20 Users Account Lockout Report

It may be exactly what you are after but if you create a report to show all users whose account have locked out and then drag the "User" field up so that its sorted on user it will show you the users at a high level and how many lockouts they have had. You can then right click the "User" field and select "Sort by Item Count"

Hope that helps

Got it. Now can we have plotted on a Bar Chart?

It works!!

Sounds like you have found it but for completeness you can turn this report into a pie or line graph by clicking on one of the icons that appear when you drag the "User" field up