The British blockade of the Mediterranean immediately cut Italy off from 80% of its imports. Essential items such as pasta, flour and rice were severely rationed, leading to riots, and any farmer withholding his crops from compulsory storage could be imprisoned for a year. Following their disastrous invasion of Greece from occupied Albania on 28 October 1940, Italian reserves of rubber, cotton, wool and other commodities began to dwindle, and the high prices charged by Germany to haul coal across the Alps from Trieste made heat a luxury. On 11 November Britain scored a major victory against the Italian navy at Taranto, which secured British supply lines in the Mediterranean.