Cleveland-based University Hospitals marked its strongest year ever in 2007, netting an operating income of $104 million. The amount is nearly four times the $28 million earned in 2004. The system also posted operating losses from 1994 through 2003, said University representatives. The biggest challenges for University Hospitals this year are likely to be uncertainties posed by a presidential election year and state budget shortfall, as well as continued progress on its strategic plan, the representatives added.