condition mean min max ZT0-3 13.95 13.95 13.95 ZT4-7 6.9 6.9 6.9 ZT8-11 39.85 39.85 39.85 ZT12-15 11.600000000000001 11.600000000000001 11.600000000000001 ZT16-19 17.1 17.1 17.1 ZT20-23 15.649999999999999 15.649999999999999 15.649999999999999