condition mean min max ZT0-3 8.93999 8.93999 8.93999 ZT4-7 4.545755 4.545755 4.545755 ZT8-11 5.54765 5.54765 5.54765 ZT12-15 7.862875 7.862875 7.862875 ZT16-19 8.133234999999999 8.133234999999999 8.133234999999999 ZT20-23 8.555645 8.555645 8.555645