While we cannot really define what constitues a healthy s*x life, we can now determine how often should make love with our partner. In 2005, the Kinsey Institute conducted a research which took into consideration the participant’s age came to these results:
18-29: on average 112 times a year
As you might’ve guessed, younger adults are having the most s*x.
30-39 years: on average 86 times a year
Many things change during your thirties. When you reach this age, normally, you choose to settle down in your career, get married, and start your own family, but not all do. Eighty-six times is the average count for this bracket, which equates to at least once per week.
40-49 years: on average 69 times a year
Sixty-nine times per year is the average count for middle-aged couples—which means 1.3 times annually. As you can see, the older you get and the bigger the family becomes, the less frequent s*x happens.  

Some people shared that they are having the best s*x of their life in their fifties. According to a blog, Best of Everything After 50, they have a lot more free time in their fifties given that they were focused on raising the children in previous years.
Around half percentage of the couples in their sixties and seventies continue to be s*xually active but this number drops to a fourth in ages 75 and up, according to a study by the National Survey of S*xual Health and Behavior.