What should my muscle mass percentage goal be?

im female, 22 yrs old and i want to gain more muscle and lean up a little i have a scale that shows the body fat % and muscle mass %. right now i'm 5'7 ,142 lbs, and my body fat percent is 22 and muscle mass is only 40 percent:( iv been 43% in the past but iv never really been that fit so i wanted to exceed 43% im just not sure what my goal should be. i don't want to be going to any body builder competitions just a good balance of muscle and fat? so whats a healthy muscle mass percentage?