Survival rates

Hi,

I'd like to make a projection of a country's population increase by age group. I found data on death by age groups here:
http://esa.un.org/unpd/wpp/Excel-Data/mortality.htm
My problem is to compute the survival rates from that. If I simply (and, I guess, wrongly) subtract the number of deaths from 1, the obtained rates do not decrease as age increases, contrary to what survival rates should look like.

Thanks for your help!