The share of tourists needing a visa to travel is at its lowest point ever, according to the most recent visa openness report, released this month by the United Nation’s World Tourism Organization (UNWTO).

In 2015, 39% of the world’s population could travel for tourism purposes without needing to obtain a traditional visa before leaving, compared to 23% in 2008.

About 18% of the world’s population was able to travel without a visa in 2015, while 15% could get a visa on arrival and 6% could get eVisas.

The UNWTO advocates for the need to advance the ease of travel “as a means to promote tourism development and multiply its socio-economic benefits”.

The report notes that many travellers see visas as a formality with a cost. If the costs, which include both the price and the length and complexity of the process, are too much, travellers are deterred from making that journey. Inadequate visa policies can stifle a country’s tourism sector, according to the UNWTO.

There is much disparity between which countries are open to tourists without visa requirements, as some let almost anyone enter freely, while others require almost all nations to get a visa.

Emerging economies are more open to tourists than advanced ones, according to the report. South-East Asian, East African, Caribbean and Oceanian destinations are the most open to tourists without visa, and in contrast, Central African, North African and North American are the strictest when it comes to requiring visas.

The UNWTO’s Secretary-General, Taleb Rifai, said in a statement that current security challenges shouldn’t deter countries from advancing visa facilitation.

“On the contrary, enhancing security and facilitating tourism travel should always go hand in hand”.