I think that's measurement of your lung capacity?
I know mine is 80%. I can't tell a difference except when my asthma is pestering me.
Lupus, Fibromyalgia, Glaucoma, Asthma, Hypothyriodism, Sleep Apnea, OA, Depression, Allergies, and benign familia tremors
When life throws you lemons....
Pick them up and throw them right back at them! :))