The USC Annenberg School Center for the Digital Future found that, in 2009, 30.5% of Americans felt uncomfortable with the lack of face-to-face contact when ordering a product online. The corresponding percentage was 23.5% in 2001. Assume the samples were independently and randomly selected and that the sample size was 2000 in both years.

Find a 99% confidence interval for the difference in population proportions of those uncomfortable with lack of face-to-face contact for the two years. (Let group 1 represent 2009.)