Aug. 26 (UPI) -- The success rate of climbers attempting to summit Mount Everest has doubled over the last 30 years, despite a dramatic increase in climbing traffic. But research published Wednesday in the journal PLOS One suggests the death rate remains flat at 1 percent.
For the study, scientists analyzed the success and death rates of climbers who received a permit to climb Everest between 2006 and 2019. The same researchers previously analyzed the results of summiting attempts made between 1990 and 2005.
"Reported statistics of risk on Everest are often inaccurate," lead study author Raymond Huey said in a news release.
"By analyzing climbing data, we provide accurate information on the chances of success and on the chances of dying, thereby helping climbers make an informed decision about whether to attempt this great peak," said Huey, a professor emeritus of biology at the University of Washington.
To get a better sense of the risk, researchers focused only on first-time climbers who secured official permits to climb the world's tallest peak.
Between 1990 and 2005, 2,200 first-time climbers attempted to summit Everest. More than 3,600 climbers made their first attempt between 2006 and 2019. The data showed the summiting success rate of climbers between 2006 and 2019 was twice that of climbers who set out from base camp between 1990 and 2005.
Today, roughly two-thirds of climbers reach the summit. Thirty years ago, just one-third of climbers successfully summited Mount Everest.
Despite the presence of more and more climbers on the mountain, researchers found the death rate has remained unchanged over the last 30 years -- stable at 1 percent.
Researchers also analyzed the relationships between age, sex and prior climbing experience and the success and death rates of climbers, finding that more women are attempting to climb Mount Everest. According to the data, me and women have the same odds of success and death.
Scientists cited several reasons for the increasing success rate -- weather forecasting has improved significantly, allowing climbers to pick safer windows during which to try for the summit; many of the most popular climbing routes now have permanently fixed ropes; and more climbers are also using supplemental oxygen, and using it earlier, at lower elevations.
Demand for Mount Everest climbing permits has grown in recent years, but researchers found no evidence that crowding near the summit has influenced success or death rates.
The research was made possible by the Himalayan Database, a website dedicated to documenting climbers, expeditions and summit successes for Everest and hundreds of other Nepalese peaks. The site was founded by Elizabeth Hawley, a Chicago-born journalist who spent most of her adult life in Nepal.
Hawley, who served as a news correspondent for Reuters in Kathmandu, began chronicling Himalayan climbing expedition in the 1960s. She continued keeping climbing records until her death in 2018. Today, the project continues under new leadership.
"It's a remarkable data source," Huey said. "She was legendary -- climbers used to say you have not climbed Mount Everest until Ms. Hawley says you've climbed Mount Everest."