The popularity of the Four Days Marches continued to increase, breaking the 10,000 barrier in 1954. The participation in 1967 of Prince Claus, husband of Queen Beatrix, helped to boost the event's popularity yet further, with over 20,000 taking part in 1982 and 30,000 by 1988. The number of participants now regularly exceeds 40,000. Due to this growth, since 2004 there has been an upper limit on the number taking part, with a record 48,986 registering for the 100th March in 2016. This increase has been boosted by a rising number attending from across the world. In 2019 6,347 non-Dutch walkers from 73 countries took part.