condition mean min max ZT0-3 9.1 9.1 9.1 ZT4-7 38.2 38.2 38.2 ZT8-11 13.35 13.35 13.35 ZT12-15 11.95 11.95 11.95 ZT16-19 13.100000000000001 13.100000000000001 13.100000000000001 ZT20-23 8.25 8.25 8.25