Thanks for the correction. I assumed my general statement wouldn't be universally correct, but I didn't expect the number of exemptions to be nearly that high.
I wish it were true, but it's not. Many people are exempt from service on racial, religious or just ideological reasons. Mind you, it's not always easy to be exempt, but some sectors of the population have an automatic "pass".
Every Israeli adult is ex-IDF, except for those adults who are still in the IDF.