condition mean min max ZT0-3 1740.693595 1740.693595 1740.693595 ZT4-7 289.9739325 289.9739325 289.9739325 ZT8-11 312.30461949999994 312.30461949999994 312.30461949999994 ZT12-15 518.9808265 518.9808265 518.9808265 ZT16-19 1095.814662 1095.814662 1095.814662 ZT20-23 1058.590847 1058.590847 1058.590847