condition mean min max ZT0-3 9.899391 9.899391 9.899391 ZT4-7 10.338912 10.338912 10.338912 ZT8-11 10.9683505 10.9683505 10.9683505 ZT12-15 10.109502500000001 10.109502500000001 10.109502500000001 ZT16-19 10.0620695 10.0620695 10.0620695 ZT20-23 9.914919000000001 9.914919000000001 9.914919000000001