...Standard & Poor's Ratings Services lowered its underlying rating (SPUR) to '###+' from 'A-' on the Illinois Educational Facility Authority's series 2005 adjustable-rate demand revenue bonds issued for Illinois College (IC). The outlook is stable. Standard & Poor's also affirmed its '###/A-1+' rating on the authority's series 2005 bonds issued for IC, based on our application of joint criteria. The '###' long-term rating is jointly based on the ratings on IC and on the letter of credit (LOC) provider, U.S. Bank N.A., assuming low correlation. The 'A-1+' short-term rating is based on the short-term rating on U.S. Bank. Based on our revised criteria published Jan. 6, 2016, we have assessed the college's enterprise profile as vulnerable, with recent freshmen and full-time-equivalent enrollment declines, adequate student quality, high discount rate, and weakening net tuition revenue. We have assessed the college's financial profile as vulnerable, reflecting our view of IC's weak operating performance...