How much vaginal fluid do you get throughout the month?

I'm interested to see how much vaginal fluid is normal throughout the month. I feel like I'm drying out and my underwear doesn't get "dirty" like it used to when I was younger. Am I drying out? How many women still get "wet underwear" from their fluids and how many always have dry underwear. Please let me know your age! I'm only 23, 24 in December and I had my first child 4 years ago. Only one kid.