condition mean min max ZT0-3 1.666415 1.666415 1.666415 ZT4-7 0.606759 0.606759 0.606759 ZT8-11 0.6726749999999999 0.6726749999999999 0.6726749999999999 ZT12-15 1.756925 1.756925 1.756925 ZT16-19 3.457855 3.457855 3.457855 ZT20-23 3.020295 3.020295 3.020295