“…PC has a worldwide distribution, with a variable rate up to 80%. 2,3 Its prevalence has increased worldwide since the middle of the 1960s. 4 In certain epidemiologic school surveys conducted in different countries, the prevalence of PC has been found to be 15% in France, 5 37.2% in Korea, 6 33.7% in Australia, 7 9.39% in Spain, 8 40% in Taiwan, 9 78.6% in Libya, 5 8% in Lebanon, 10 13.4% in northern Jordan, 11 55% in Israel, 12 and 28.3% in the UK.…”