condition mean min max ZT0-3 3.62273 3.273815 3.8690499999999997 ZT4-7 3.8055899999999996 3.8055899999999996 3.8055899999999996 ZT8-11 2.9359349999999997 2.9359349999999997 2.9359349999999997 ZT12-15 4.181495 4.005269999999999 4.3577200000000005 ZT16-19 3.786645 3.786645 3.786645 ZT20-23 4.53534 4.53534 4.53534