COVID-19 is especially hard on the old and frail, with 79% of the deaths attributed to the disease in the U.S. among those 65 and older and 94% among people with at least one "comorbidity" such as diabetes, dementia, obesity or hypertension. 2020 is likely to see big increases in overall mortality. Because of the age profile of the disease, though, the life expectancy decline would be less historic. In a study that estimated 11.7 average years of life lost by U.S. COVID victims, University of California at Berkeley demographers Joshua R. Goldstein and Ronald D. Lee also estimated that 250,000 additional deaths due to the disease would decrease average U.S. life expectancy at birth by about 10 months (0.84 years) - the biggest one-year drop since World War II but smaller than decreases in 1943 and several years in the 1920s and 1930s (mostly due to bad flu seasons), and just a fraction of the staggering 11.8-year decline in 1918.