Statistical Analyses: The numbers of person-years at risk of developing and dying for ovarian cancer will be calculated. Incidence rates will be calculated by dividing the number of ovarian cancer cases by the person-years at risk of developing ovarian cancer. Mortality rates will be calculated by dividing the number of ovarian cancer deaths by the person-years at risk of dying from ovarian cancer. The association between mortality and age, histology, time periods will be estimated through Kaplan-Meier survival analysis and Cox's proportional hazards model. It is defined as significantly different statistically when p value is less than 0.05.