Of note, however, son-preference in urban areas lias declined over the years due to the empowerment of women and higher gender equality. They are found to be lower than their maximum value as a result of delayed marriage and marital disruption, the use of contraception and induced abortion and post-partum infecundability (Bongaarts, 1982). The indices of marriage, contraceptive use, induced abortion and postpartum infecundability, as well as the TFR and TF, as obtained from the Bongaarts model for the years 1997 and 2002 by residence are presented in table 5.