The EU external borders have come under strain from a surge in the number of border crossings, both regular and irregular. According to a Commission communication of April 2016, the number of non-EU citizens travelling to the EU increased from 49 million (191 million border crossings) to 50 million (200 million border crossings), between 2014 and 2015. According to a study by the UN World Tourism Association (UNWTO), the number of international tourist arrivals (not persons, who may be counted multiple times) in the 28 EU grew from 331 million to 433 million, between 2000 and 2013 (see Figure 1). In about one third of cases, the travellers arrived from non-EU countries. According to a report by PwC, the number of non-EU travellers to the EU is estimated to rise to 76 million by 2025. The UNWTO study forecasts that the number of international tourist arrivals to the EU will grow to reach 558 million by 2030 (of which, 200 million arrivals from non-EU countries).