The interest towards Sofia is great as the increase in the number of passengers at Sofia Airport and in the number of guests in the city is noticeable. In 2017, the number of passengers at Sofia Airport increased by 30.3% - the greatest growth in Europe. The number of passengers reached 6.5 millions - 3 millions more compared to 2013. Reykjavik Airport (29.2%) is the only one that can compete with us but there over 1/3 of the traffic consists of transit flights. The number of passengers at the three main airports in Portugal increased by 15-17% and Bucharest and Krakow reported an increase of about 17%. Some of the factors that contributed to this growth are the Bulgarian Presidency of the Council of the EU, the low-cost flights, the accommodation applications, and the free roaming.