condition mean min max ZT0-3 10.4627875 9.605175 11.3204 ZT4-7 8.03454 8.03454 8.03454 ZT8-11 6.20132 6.20132 6.20132 ZT12-15 0 0 0 ZT16-19 7.09964 7.09964 7.09964 ZT20-23 11.74775 11.74775 11.74775