condition mean min max ZT0-3 18.455525 15.8586 21.05245 ZT4-7 17.624499999999998 17.624499999999998 17.624499999999998 ZT8-11 12.907599999999999 12.907599999999999 12.907599999999999 ZT12-15 0 0 0 ZT16-19 4.63111 4.63111 4.63111 ZT20-23 9.78761 9.78761 9.78761