The pulse of normal people when they are quiet:
Adult male is about 60-80 times/minute.
70-90 times/minute for women.
Pulse decreases when falling asleep:
For men, it is about 50-70 times per minute.
For women, the frequency is about 60-70 times per minute.
Some people can be as low as 45-50 times per minute.
Don't worry! Your situation is normal if there are no other problems. It may be related to your physical fitness and your usual exercise.