condition mean min max ZT0-3 15.573312 15.573312 15.573312 ZT4-7 17.7872695 17.7872695 17.7872695 ZT8-11 16.622364 16.622364 16.622364 ZT12-15 17.3453245 17.3453245 17.3453245 ZT16-19 17.9481455 17.9481455 17.9481455 ZT20-23 15.9254405 15.9254405 15.9254405