condition mean min max ZT0-3 12.358006666666666 5.59457 16.0549 ZT4-7 5.059355 5.059355 5.059355 ZT8-11 5.231055 5.231055 5.231055 ZT12-15 7.023915 5.311895 8.735935 ZT16-19 8.945435 8.945435 8.945435 ZT20-23 12.18455 12.18455 12.18455