condition mean min max ZT0-3 5.09451 5.09451 5.09451 ZT4-7 5.11621 5.11621 5.11621 ZT8-11 3.176685 3.176685 3.176685 ZT12-15 2.879345 2.879345 2.879345 ZT16-19 2.10921 2.10921 2.10921 ZT20-23 4.863195 4.863195 4.863195