condition mean min max ZT0-3 8.736908333333334 7.768865 10.30694 ZT4-7 6.36388 6.36388 6.36388 ZT8-11 5.171275 5.171275 5.171275 ZT12-15 7.6313175 7.55455 7.7080850000000005 ZT16-19 7.434175 7.434175 7.434175 ZT20-23 8.72391 8.72391 8.72391