Percentage diabetic foot ulcers of patients aged 18 years or older with a diagnosis of a Wagner Grade 3, 4, or 5 diabetic foot ulcer (DFU) whose ulcer has achieved healing or closure 6 months after completion of a course of HBOT, stratified by the Wound Healing Index. Healing or closure is defined as an ulcer with epithelial coverage and no continued drainage requiring a dressing. There are four rates reported for this measure. Three of the rates will be risk stratified into three buckets (minimum-maximum) which are the following: Rate 1: 0.00-62.42 Rate 2: 62.42-73.19 Rate 3: 73.19-93.45 Rate 4: The average of the three risk stratified buckets which will be the performance rate in the XML submitted.