Sometimes people have a screenshot and they painstakingly go over the numbers. Manually reading the numbers and typing it out in notepad. Then use the calculator in windows to find the sum, average etc.
I found this recently in my team, where some of us were actually looking at the VSTS tables while the run was going on, typing out the numbers (eg: cpu, memory etc) into notepad and finding the average using excel.
Well, not anymore! Here is the solution using image recognition software.
Solution: Use an image recognition software like "JOCR" (thanks to Sreedhar D) uploaded to "\\nftparing box\D\SOFT\ImageRecognition.exe". When the software is run, it asks for the area to capture. Drag a screen area around the table (or the screenshot) u want to capture. The output would be a set of numbers. Copy paste into Excel and click on the "Average" button in Excel. And you are done!