According to the researcher Andrei Lankov, both the extreme high and low ends of the estimates are considered inaccurate.[49] In 2001 and 2007, independent groups of researchers have estimated that between 600,000 to 1 million people, or 3 to 5 percent of the pre-crisis population, died due to starvation and hunger-related illness.[50][51] In 1998, US Congressional staffers who visited the country reported that: "Therefore, we gave a range of estimates, from 300,000 to 800,000 dying per year, peaking in 1997. That would put the total number of deaths from the North Korean food shortage at between 900,000 and 2.4 million between 1995 and 1998".[52] W. Courtland Robinson's team found 245,000 "excess" deaths (an elevated mortality rate as a result of premature death), 12 percent of the population in one affected region. Taking those results as the upper limit and extrapolating across the entire North Korean population across the country's provinces produces an upper limit of 2,000,000 famine-related deaths.[53] Andrew Natsios and others estimated 2-3 million deaths.[54][7]