Source: http://www.ressources-actuarielles.net/EXT/ISFA/1226-02.nsf/d512ad5b22d73cc1c1257052003f1aed/50c1aa1ea035bd41c125767e0071ec08/$FILE/%20M%C3%A9moire%20Actuariat%20Ben%20DBABIS%20Makram.pdf