What is the amount of fasting that must be observed annually to make up for about ten missed Ramadans, and what is the permissible delay without incurring sin?

There is no harm in breaking the fast in Ramadan for the sick, due to the Almighty's saying: "And whoever is ill or on a journey - then an equal number of other days." There is no expiation for delaying the make-up fast if it is due to an excuse, such as illness. Whoever's excuse has ceased should begin making up the fasts he missed from previous Ramadans. Making up the fasts immediately or consecutively is not obligatory according to most scholars. One should try to make up the fasts before the next Ramadan. If one is unable to do so due to an excuse, there is no sin upon him nor expiation for the delay. There is no specific amount for making up fasts annually. As for the forbidden delay, it is delaying the make-up fast such that there is not enough time remaining before the next Ramadan. Whoever is excused in delaying the make-up fast is permitted to delay it, even if Ramadans are repeated, and no expiation is required of him; he only has to make up the fasts.