The city' s center for disease control reports that the rabies epidemic is more serious now than it was two years ago: 2 years ago less than 25 percent of the local raccoon population was infected, whereas today the infection has spread to more than 50 percent of the raccoon population. However, the newspaper reports that whereas two years ago 32 cases of rabid raccoons were confirmed during a 12-month period, in the past 12 months only 18 cases of rabid raccoons were confirmed. Which one of the following, if true, most helps to resolve the apparent discrepancy between the two reports? ['Since the outbreak of the epidemic, raccoons, which are normally nocturnal, have increasingly been seen during daylight hours.', 'A significant proportion of the raccoon population succumbed to rabies in the year before last.', 'The number of cases of rabies in wild animals other than raccoons has increased in the past 12 months.', 'The symptoms of distemper, another disease to which raccoons are susceptible, are virtually identical to those of rabies.']