condition mean min max ZT0-3 16.449591 16.449591 16.449591 ZT4-7 14.548747500000001 14.548747500000001 14.548747500000001 ZT8-11 17.9588945 17.9588945 17.9588945 ZT12-15 20.904804499999997 20.904804499999997 20.904804499999997 ZT16-19 21.808931 21.808931 21.808931 ZT20-23 16.3704575 16.3704575 16.3704575