For the DOS, we are interested in the time to drop out of the study.

(a) Create a life table including the number of subjects at risk, the number of failures (new depression), the number of survivors, and the number of the censored subjects for each gender, at each year;

(b) Create a life table including the estimated discrete hazards and survival functions and their associated standard deviations stratified for each gender at each year. Indicate how the censoring is handled.