Recent research shows that increasing shortages in honeybees threaten pollination of crops in Europe. Although according to a study covering 41 European countries the overall number of honeybee stocks has increased by 7 per cent between 2005 and 2010 (to an estimated 13.4 million colonies with 7 billion honeybees), 15 countries have also experienced declines ranging from 4 per cent in Slovenia to 47 per cent in Switzerland. At the same time have changes in agricultural practices led to considerable changes in the need for pollination. Increases in pollinated crop areas are contributed to the growth of areas for producing biofuel crops (oilseed rape, sunflower and soybean), as have the use of pesticides led to a decline in the number of bees.