Some historians believe the pandemic began in China or Central Asia (one such location is Lake Issyk Kul)[5] in the lungs of the bobac variety of marmot, spreading to fleas, to rats, and eventually to humans.[6] In the late 1320s or 1330s, merchants and soldiers carried it over the caravan routes until in 1346 it reached the Crimea in South Eastern Europe. Other scholars believe the plague was endemic in that area. In either case, from Crimea the plague spread to Western Europe and North Africa during the 1340s.[7][8] The total number of deaths worldwide is estimated at 75 million people,[9] approximately 25–50 million of which occurred in Europe.[10][11] The Black Death is estimated to have killed 30% to 60% of Europe's population.[12][13][14] It may have reduced the world's population from an estimated 450 million to between 350 and 375 million in 1400.[15]