condition mean min max ZT0-3 3.76036 3.76036 3.76036 ZT4-7 2.478925 2.478925 2.478925 ZT8-11 3.0404600000000004 3.0404600000000004 3.0404600000000004 ZT12-15 5.195905 5.195905 5.195905 ZT16-19 6.748315 6.748315 6.748315 ZT20-23 4.97548 4.97548 4.97548