condition mean min max ZT0-3 1.875975 1.875975 1.875975 ZT4-7 1.423235 1.423235 1.423235 ZT8-11 1.430275 1.430275 1.430275 ZT12-15 1.7461799999999998 1.7461799999999998 1.7461799999999998 ZT16-19 2.27848 2.27848 2.27848 ZT20-23 1.83536 1.83536 1.83536