Is zakat due on the lowest balance that reached the nisab and remained for a full year (EGP 11,000), or on the final amount (EGP 19,300)?

The nisab (minimum threshold) becomes obligatory when wealth reaches the value of 85 grams of pure gold or 595 grams of pure silver. The hawl (one lunar year) is calculated using the Hijri months. Acquired wealth is of two types:

First: Growth of the original capital (e.g., profit from trade). This is subject to zakat along with the original capital.

Second: Wealth not originating from the growth of original capital (e.g., inheritance, saved salary). Here, scholars differed: The madhhab of Abu Hanifa holds that it is subject to zakat along with the original capital. The madhhab of the majority, however, states that a separate hawl should be initiated for it. This latter view is more correct, based on the hadith: "Whoever acquires wealth, there is no zakat due on it until a year has passed over it."

If the acquired wealth is part of the original capital (like profit from trade), then you pay zakat on all the wealth you possess when the hawl is completed. However, if it is not from the growth of original capital, then you pay zakat on each gain when its hawl is completed. Alternatively, it is permissible to adopt the view of Abu Hanifa and pay zakat on all wealth when the original capital's hawl is completed, as a facilitation.