condition mean min max ZT0-3 8.0 8.0 8.0 ZT4-7 8.7 8.7 8.7 ZT8-11 9.65 9.65 9.65 ZT12-15 14.75 14.75 14.75 ZT16-19 17.5 17.5 17.5 ZT20-23 10.200000000000001 10.200000000000001 10.200000000000001