condition mean min max ZT0-3 18.480233333333334 13.56155 23.01305 ZT4-7 8.443825 8.443825 8.443825 ZT8-11 5.823515 5.823515 5.823515 ZT12-15 5.7168375000000005 4.3728299999999996 7.0608450000000005 ZT16-19 7.555235 7.555235 7.555235 ZT20-23 12.2667 12.2667 12.2667