My data has a number of hospitals which are in 52 different states. Some hospitals belong to a health system. Each health system has hospitals in different states but not in all states. Some hospitals dont belong to any health system. I want to make a graph that shows only state that have hospitals with one specific healthcare system, then find the avearage readmission rate(given for each hospital) for a specific condition,five conditions in all(all conditions in the same column) for the health system using the readmission rates for the hospitals which belong to the health system. Finally devide the health systems' readmission rate with each state's readmission rate.(only the states with hospitals in this health system). Please help.