condition mean min max ZT0-3 296.651707 296.651707 296.651707 ZT4-7 201.018841 201.018841 201.018841 ZT8-11 205.2223035 205.2223035 205.2223035 ZT12-15 249.9606195 249.9606195 249.9606195 ZT16-19 285.508228 285.508228 285.508228 ZT20-23 347.607013 347.607013 347.607013