condition mean min max ZT0-3 19.102816666666666 11.6665 23.7878 ZT4-7 10.972249999999999 10.972249999999999 10.972249999999999 ZT8-11 17.488300000000002 17.488300000000002 17.488300000000002 ZT12-15 27.48795 26.5349 28.441000000000003 ZT16-19 36.8812 36.8812 36.8812 ZT20-23 47.8187 47.8187 47.8187