condition mean min max ZT0-3 7.10166 7.10166 7.10166 ZT4-7 5.623855000000001 5.623855000000001 5.623855000000001 ZT8-11 6.31725 6.31725 6.31725 ZT12-15 7.4568449999999995 7.4568449999999995 7.4568449999999995 ZT16-19 7.75803 7.75803 7.75803 ZT20-23 8.70224 8.70224 8.70224