condition mean min max ZT0-3 16.545625 16.545625 16.545625 ZT4-7 19.7326505 19.7326505 19.7326505 ZT8-11 15.783931 15.783931 15.783931 ZT12-15 17.689091 17.689091 17.689091 ZT16-19 19.0673765 19.0673765 19.0673765 ZT20-23 16.6850125 16.6850125 16.6850125