Indexing is wrong to me

yasaswi gomes (My grammar is 💯 good I)   (7290 Points)

15 July 2021  

Hi,

I recently learnt about CII used for measuring fair value changes used for selling properties.

I read CII table and for 2011 it is 200₹ and 2021 it is 300₹.

House was purchased in 2011 for 10,000₹ as per the CII 

Now when I am selling it, value of home in  2011*CII for 2021.

Why should 2021 CII be divided with 2011 CII? Any mathematical principle?