Case-Shiller Home Price Index - Need help understanding the data.

[Molly Ivey]

I would like to know the average price increases in my market by percentage (so that I can include it in a property value increase in a buy & hold analysis). I usually use trend graphix but they only go back 15 years and I'd like to go back 30 years so I was looking at the case-shiller home price index and after trying to find the answer on my own, I cannot figure out how to convert this data into percentages. 

Thank you in advance for reading this and any advice!