condition mean min max ZT0-3 25.54667 25.54667 25.54667 ZT4-7 19.007528999999998 19.007528999999998 19.007528999999998 ZT8-11 18.6413565 18.6413565 18.6413565 ZT12-15 18.36385 18.36385 18.36385 ZT16-19 18.787816999999997 18.787816999999997 18.787816999999997 ZT20-23 17.563083 17.563083 17.563083