condition mean min max ZT0-3 1.2843975 0.865835 1.948795 ZT4-7 2.2450200000000002 2.2450200000000002 2.2450200000000002 ZT8-11 9.163645 9.163645 9.163645 ZT12-15 12.107425 11.56035 12.6545 ZT16-19 6.08685 6.08685 6.08685 ZT20-23 5.296085 5.296085 5.296085