condition mean min max ZT0-3 4.139615 4.139615 4.139615 ZT4-7 9.44496 9.44496 9.44496 ZT8-11 5.68688 5.68688 5.68688 ZT12-15 5.17872 5.17872 5.17872 ZT16-19 1.5283350000000002 1.5283350000000002 1.5283350000000002 ZT20-23 2.440975 2.440975 2.440975