condition mean min max ZT0-3 9.368883 9.368883 9.368883 ZT4-7 9.2979335 9.2979335 9.2979335 ZT8-11 9.1120475 9.1120475 9.1120475 ZT12-15 8.8665475 8.8665475 8.8665475 ZT16-19 9.509749 9.509749 9.509749 ZT20-23 11.535783 11.535783 11.535783