(St. Paul, MN) -- Mayo Clinic says it will spend five billion dollars over the next 20 years to "protect its current status as one of the world's premier medical institutions" -- and is asking the state to finance about 600 million dollars to upgrade public infrastructure in Rochester. Mayo executives say improvements are needed to continue to draw patients from around the country and the world. President and C-E-O, Doctor John Noseworthy, says Mayo's facilities in Florida and Arizona had done "extraordinarily well", but Mayo Clinic in Minnesota is "the leading brand in health care in the world" and they don't want to leave the state. Noseworthy says Mayo is not asking for a handout from taxpayers and none of the money would go toward Mayo facilities. He says infrastructure improvements would be funded by state appropriation bonds, paid back with a percentage of tax revenue generated by the Mayo expansion.