condition mean min max ZT0-3 371.770518 371.770518 371.770518 ZT4-7 377.9070605 377.9070605 377.9070605 ZT8-11 501.059999 501.059999 501.059999 ZT12-15 532.4696254999999 532.4696254999999 532.4696254999999 ZT16-19 442.1020475 442.1020475 442.1020475 ZT20-23 447.9631185 447.9631185 447.9631185