A new study suggests smokers who quit try to give up cigarettes an average of 30 times before they succeed. Previous studies indicated the number was much lower, Reuters reports.

The new study followed more than 1,200 adult smokers in Canada for up to three years. When the study began, participants told researchers how many times they remembered making a serious attempt to quit smoking. At each six-month follow-up visit, they reported how many times they had seriously tried to quit smoking during the previous six months. Researchers considered a quit attempt to be successful when a person was smoke free for at least one year.

Previous studies have suggested people try quitting an average of five to seven times before succeeding.

“For so long we’ve been talking about five to seven attempts to quit,” said lead author Dr. Michael Chaiton of the University of Toronto. “For us (the numbers) were a lot higher.” He noted previous studies were based on the lifetime recollections of people who had quit. They did not include quit attempts by people who had not yet successfully quit smoking. “People are very bad at remembering over their whole lifetimes,” Chaiton told Reuters. “The second problem is we were only asking people who have been successful at quitting.”

The results appear in the journal BMJ Open.

Chaiton noted that some people are able to quit smoking more quickly than others. “This doesn’t mean you hit a magic number and then you can quit,” he said. “There are many people who are able to and do quit on their first attempt or in the first few. There are people who are good at many things. Some are good at quitting smoking.”