Return Calculation of Nifty

Dear All,

How to find the weekly, monthly, 6 month, yearly and YTD return calculation of Nifty using excel. If you go to the moneycontrol site they have arrived returns of nifty as follows:-

Weekly - -0.20%
Monthly - 0.20%
Yearly - 20%
YTD - 17.28%

Just wondering how they arrived at this calculations. If anybody know do explain it to me in excel.

use function =LN(currentdateclose / pervious6monthclose)/ 2

Well ur calculation is wrong. I did my workings in excel but its not giving the correct returns when compared with site.