condition mean min max ZT0-3 1.96539 1.96539 1.96539 ZT4-7 4.452389999999999 4.452389999999999 4.452389999999999 ZT8-11 7.399890000000001 7.399890000000001 7.399890000000001 ZT12-15 6.450899999999999 6.450899999999999 6.450899999999999 ZT16-19 6.74048 6.74048 6.74048 ZT20-23 6.461566666666666 6.461566666666666 6.461566666666666