condition mean min max ZT0-3 6.572635 5.482585 8.65775 ZT4-7 4.46338 4.46338 4.46338 ZT8-11 6.936780000000001 6.936780000000001 6.936780000000001 ZT12-15 10.2466775 9.93885 10.554504999999999 ZT16-19 8.24955 8.24955 8.24955 ZT20-23 8.92431 8.92431 8.92431