Participants provided information about how frequently they had used marijuana and other drugs over a period of years
Los Angeles is considered the world's largest pot market
Will be held during 2020 elections
Canada legalised recreational marijuana use on Oct 17
Statistics Canada says 5.4 million Canadians will buy cannabis from legal dispensaries in 2018
Oregon's marijuana tax receipts from January also surpassed the first-month tallies from recreational cannabis sales
Italy, Switzerland and Bulgaria rounded out the top five