My knees used to click all the time when I was your age (god it makes me feel old to say 'when I was your age'! I'm only 24 now!)
I never drank any tea or coffee ever though. I think some people are just more clicky than others. If it makes you feel better - for some reason it's not as bad as it used to be, dunno why?!

My joints click too and i'm 27

I do have weak bones though, as i suffer with a spinal condition