condition mean min max ZT0-3 9.957663333333333 7.5747 13.21619 ZT4-7 15.9055 15.9055 15.9055 ZT8-11 11.9038 11.9038 11.9038 ZT12-15 29.145825 18.7926 39.49905 ZT16-19 11.431905 11.431905 11.431905 ZT20-23 9.559685 9.559685 9.559685