condition mean min max ZT0-3 4.588146666666667 2.38917 8.20666 ZT4-7 2.1715679999999997 2.1715679999999997 2.1715679999999997 ZT8-11 6.666505 6.666505 6.666505 ZT12-15 12.5274575 9.584465 15.47045 ZT16-19 7.331605 7.331605 7.331605 ZT20-23 4.888925 4.888925 4.888925