condition mean min max ZT0-3 25.59505528 22.15709598 29.03301458 ZT4-7 16.3048217825 15.302402990000001 17.307240574999998 ZT8-11 16.7022523425 16.30481399 17.099690695 ZT12-15 11.95797876775 10.460064029 13.455893506499999 ZT16-19 11.903142664999999 11.091334029999999 12.7149513 ZT20-23 16.041591259999997 14.892129115 17.191053404999998