condition mean min max ZT0-3 9.8800975 8.626445 11.13375 ZT4-7 7.624285 7.624285 7.624285 ZT8-11 7.1222449999999995 7.1222449999999995 7.1222449999999995 ZT12-15 0 0 0 ZT16-19 10.810839999999999 10.810839999999999 10.810839999999999 ZT20-23 11.7872 11.7872 11.7872