To mark World Religion Day, a Bahá'í initiative started in the 1950s, we've mapped the world's most - and least - religious countries. We've based our map on the results of three WIN/Gallup International polls, taken in 2008, 2009 and 2015. Each asked respondents whether or not they felt religious; for each country we've included the most recent figures available.

According to the surveys, five countries tie for the title of most religious. In each of Ethiopia, Malawi, Niger, Sri Lanka and Yemen, 99 per cent of those questioned answered "yes". A further four - Burundi, Djibouti, Mauritania and Somalia - saw 98 per cent reply in the affirmative.

A temple in Luang Prabang, Laos Credit: frenta - Fotolia/Lukiyanova Natalia

The 20 most religious countries

Ethiopia - 99% feel religious Malawi - 99% Niger - 99% Sri Lanka - 99% Yemen - 99% Burundi - 98% Djibouti - 98% Mauritania - 98% Somalia - 98% Afghanistan - 97% Comoros - 97% Egypt - 97% Guinea - 97% Laos - 97% Myanmar - 97% Cambodia - 96% Cameroon - 96% Jordan - 96% Senegal - 96% Chad - 95% (six other countries - Ghana, Mali, Qatar, Republic of the Congo, Rwanda and Zambia - also returned a result of 95%)

As the map demonstrates, the most religious regions are Africa and the Middle East, with south-east Asia and Latin America not far behind. Faith is important to many southern European countries too, with 74 per cent of Italians and 71 per cent of Greek claiming to feel religious.

A chapel in Lefkada, Greece Credit: Aleksandar Todorovic - Fotolia

Poland stands out against the rest of Europe, with 86 per cent answering "yes" to the poll; Paraguay would appear to be South America's most religious country.

Around three in 10 Britons feel religious, the polls suggest, compared to 56 per cent of Americans.

The least religious countries, on the other hand, include Japan, Estonia, Sweden, Norway and the Czech Republic, but China surpasses them all, with only seven per cent.

The vast majority of Chinese do not feel religious, according to the polls Credit: Credit: Sean Pavone / Alamy Stock Photo/Sean Pavone / Alamy Stock Photo

The 20 least religious countries