condition mean min max ZT0-3 6.7959499999999995 6.7959499999999995 6.7959499999999995 ZT4-7 5.70868 5.70868 5.70868 ZT8-11 6.147075 6.147075 6.147075 ZT12-15 4.57271 4.57271 4.57271 ZT16-19 5.45548 5.45548 5.45548 ZT20-23 7.6686700000000005 7.6686700000000005 7.6686700000000005