Low cost airline easyJet saw a steep rise in the number of passengers carried in February from a year ago, though the gain was not as sharp as January's.The number of passengers carried on the airline's familiar white and orange planes rose 13.1% to 3.83m in February from 3.39m in February 2010.In January, the airline had reported a 19.1% year on year increase in passenger numbers.The load factor, which measures how well planes are filled, improved to 86.4% from 85.3% a year earlier and 78.9% the month before.Over a rolling 12-month period the number of passengers carried rose 8.6% to 50.76m from 46.76m in the 12 months to end-February 2010. In January, the gain in the rolling 12-month passengers number was slightly lower at 8.5%.The load factor over the 12 months to end-February 2011 rose to 87.1% from 86.1% in preceding 12 month period.