condition mean min max ZT0-3 14.668349 14.668349 14.668349 ZT4-7 13.5675435 13.5675435 13.5675435 ZT8-11 12.190737 12.190737 12.190737 ZT12-15 16.873397999999998 16.873397999999998 16.873397999999998 ZT16-19 12.935129 12.935129 12.935129 ZT20-23 23.3530705 23.3530705 23.3530705