condition mean min max ZT0-3 2.1297711025 1.018431974 3.241110231 ZT4-7 3.2681173035000004 3.0529302405000003 3.4833043665 ZT8-11 5.29105311325 3.8954106250000002 6.6866956015 ZT12-15 5.1926960775 4.246766546 6.138625609 ZT16-19 4.21202191425 3.784485581 4.6395582475 ZT20-23 4.725800996749999 3.967010973 5.4845910205