condition mean min max ZT0-3 15.768325 15.1421 16.394550000000002 ZT4-7 20.226 20.226 20.226 ZT8-11 19.575400000000002 19.575400000000002 19.575400000000002 ZT12-15 0 0 0 ZT16-19 24.40165 24.40165 24.40165 ZT20-23 23.5092 23.5092 23.5092