condition mean min max ZT0-3 3.439186666666667 2.399185 4.4179200000000005 ZT4-7 2.149105 2.149105 2.149105 ZT8-11 1.94781 1.94781 1.94781 ZT12-15 2.8755075000000003 2.80825 2.942765 ZT16-19 2.95101 2.95101 2.95101 ZT20-23 4.5975649999999995 4.5975649999999995 4.5975649999999995