condition mean min max ZT0-3 4.609515 4.33034 4.88869 ZT4-7 5.5442599999999995 5.5442599999999995 5.5442599999999995 ZT8-11 5.295030000000001 5.295030000000001 5.295030000000001 ZT12-15 0 0 0 ZT16-19 4.878035 4.878035 4.878035 ZT20-23 4.40598 4.40598 4.40598