The number of Jews in Hevron is over 850, not the 500 you claim. While their may be roughly 100 families, the yeshiva students really push up the numbers. Furthermore, most Hebronim have large families and some households have three generations living together, for lack of available housing.
Four Libyan soldiers said killed in battle with Islamists in Benghazi (Reuters)
from the article: Jewish community in Hebron wins the lottery