Ryanair, Europe's leading low-cost airline, said on Thursday its passenger numbers rose by 5 percent last month to reach a record level of 8.5 million.

The Dublin-based airline said its load factor, a measure of how much of an airline's passenger carrying capacity is used, rose last month from 85 percent to 90 percent.

Last month, Ryanair signed an agreement with Boeing to purchase up to 200 new Boeing 737 MAX 200 "gamechanger" aircraft. The deals comprised 100 firm orders and 100 options. When finalized and all options exercised, the deals will be worth over 22 billion US dollars at current list prices.

The jetliners, which will be more fuel efficient and quieter than previous 737s, are part of a push by the airline to increase its annual passenger numbers by 50 percent to 150 million per year by 2024.

Last year, Ryanair placed a 15.6 billion dollar order for 175 Boeing 737-800 jets.