condition mean min max ZT0-3 3.1720375 2.938545 3.40553 ZT4-7 2.130535 2.130535 2.130535 ZT8-11 5.1079550000000005 5.1079550000000005 5.1079550000000005 ZT12-15 0 0 0 ZT16-19 7.231529999999999 7.231529999999999 7.231529999999999 ZT20-23 3.543835 3.543835 3.543835