During 2024, a new questionnaire for the study of Danes' holiday and business trips was put into use. Together with the introduction of new calculation methods, this has resulted in the level of the number of trips for 2024 not being directly comparable with previous years. Furthermore a new questionnaire was introduced in August 2017 and fully implemented in 2018, and the data for 2018 is therefore not comparable with previous years. The share of trips by airplane is estimated on the basis of the development from 2017 to 2018 in domestic flights in table FLYV33.