What percentage of people reach age 60 without suffering from a serious ailment?

Most. Today, the majority of 60 years old have so far escaped cancer, stroke, heart attack, alcoholism, emphysema and neurodegenerative disease, our great killers. Compare this to the past, when achieving age 60 was uncommon, with deaths in childbirth, from malnutrition, pneumonia, bladder infections, childhood infections, diarrhea, and interpersonal violence were the norm.