how much time should you spend in REM sleep?

I know that the sleep track provides the time spent in each stage of sleep but what is best? How much deep sleep and REM sleep should someone be getting? I know it depends on certain info - I am female -54 years old. Just a guideline would be nice. I am not sure if this is the platform for this question. But I have searched iphone Health app and it does not provide any info.