condition mean min max ZT0-3 16.1081 14.5624 17.6538 ZT4-7 7.4741599999999995 7.4741599999999995 7.4741599999999995 ZT8-11 5.7616499999999995 5.7616499999999995 5.7616499999999995 ZT12-15 0 0 0 ZT16-19 7.182895 7.182895 7.182895 ZT20-23 9.409215 9.409215 9.409215