Testing lubes, percent change spreadsheet

Not sure if there is any interest in this but thought I would share it. As you are working on a car hopefully improving it or messing with multiple goober-lubes you see the lap times decrease showing improvement - that's good but how much was gained? The screen shot below is from a lube test of 6 products actual data. 

In the data, you will see both positive and negative percentages. This is because the base formula is tuned to see increases as a positive thing. For example, if your car starts out at 300 hp and you have some work done and now it's 500 hp that's an increase and you plugged those numbers into the percentage formula And you'll get a positive number. But in our little sport, we are always trying to decrease the time so when the second number or the improved data is less than the starting data you're going to get a negative number. So indeed, if you're making progress in the right direction and reducing your lap times, you are looking for negative percentages improvement. If you get a positive number, you're going the wrong way.

What you're seeing is a screenshot from the Mac and if there is interest or you want to copy of this, I would produce a Microsoft Excel compatible sheet that might look just ever so slightly different. PM me if you're interested in a copy