Navajo Nation marked a grim milestone on Sunday, recording more coronavirus cases per capita on its reservation than any of the 50 U.S. states.

At least 3,122 cases have been reported on Navajo Nation the largest and most populous American Indian reservation in the U.S. According to 2010 census data , about 173,776 people (including both Navajo and non-Navajo) live on the reservation. This means the reservations rate of infection is roughly 1,798 per 100,000 people.

By comparison, the states with the most known cases New York, New Jersey and Massachusetts have reported 1,751 cases per 100,000 people, 1,560 cases and 1,129 cases, respectively.

Using another figure, the Total Resident Service Area Indian Population, or TRSAIP, which is used by the U.S. government to allocate federal funds, the Navajo Nation known infection rate as of Sunday was about 1,691 per 100,000 people. That would put the Navajo Nation second, after New York state, in coronavirus infections. Navajo Nations TRSAIP is 184,630, according to data compiled by the U.S. Department of Housing and Urban Development.

There have been at least 100 virus-linked deaths on Navajo Nation. Four U.S. states have more deaths per capita than the reservation: New York, New Jersey, Connecticut and Massachusetts. The number of confirmed cases on Navajo Nation has nearly doubled in just two weeks, from 1,716 reported on April 26.

The relatively high rate of testing being done on the reservation may help explain the record rate of known infections.

Navajo Nation on Sunday reported 18,153 tests had been conducted on the reservation, or about 10,452 per 100,000 people. New York state reported over the weekend that 1.2 million people have been tested, or 6,081 per 100,000 people.

As of Sunday, about 40 U.S. counties had higher rates of infection than Navajo Nation. Trousdale, Tennessee, where an outbreak has infected hundreds of inmates and staffers at a private prison, has by far the highest number of cases per capita, with 14,175 cases per 100,000 people.