A Harvard University research team led by scientists at the school’s T.H. Chan School of Public Health conducted randomized surveys of households in Puerto Rico about their experiences during and after Hurricane Maria. From those surveys, researches concluded that somewhere around 4,645 “excess deaths” are related to the hurricane.

As precise as it may seem, this figure is only a rough estimate based on testimony from those who lived through the after-effects of the inefficient and quite frankly inhumane response to the people of Puerto Rico. Of the 3,299 households randomly selected for the survey by the research team, 38 reported deaths and the team simply extrapolated those numbers out to the total population of Puerto Rico, which is 3.4 million people, to reach their estimated figure. Though 4,645 is their estimated, the researchers say there is a 95 percent chance that the death toll is between 800 and 8,500 people. They also concluded that the mortality rate in Puerto Rico climbed an estimated 62 percent in the months following the hurricane.

The death rate itself has become somewhat contentious partly because federal and island governments have been very slow to respond to Puerto Rico as compared to other hurricanes. This study also takes note of the fact that people were without power for 83 percent of the more than 100 days it measured, stretching from the date the hurricane made landfall until the end of 2017. Both Puerto Rican residents and outside observers have long remarked that the death toll given by officials is woefully inaccurate, and this study, as inexact as it might be, only supports those views.

As Rafael Irizarry, a biostatistician on the team, tells NPR: “We saw consistent, high rates, in September, October, November, December… There’s no reason to think that on Jan. 1 this trend stops.” The team also writes in its report: “Hurricane Maria caused massive infrastructural damage to Puerto Rico… In our survey, interruption of medical care was the primary cause of sustained high mortality rates in the months following the hurricane.”

Additionally, the government of Puerto Rico commissioned a study from George Washington University’s Milken Institute School of Public Health to estimate excess deaths. Results have been delayed, but are expected to be released over the summer months. According to Carlos Mercader, executive director of the Puerto Rico Federal Affairs Administration, “We have always expected the number to be higher than what was previously reported… Both studies will help us better prepare for future natural disasters and prevent lives from being lost.”