condition mean min max ZT0-3 697.423359 697.423359 697.423359 ZT4-7 731.857442 731.857442 731.857442 ZT8-11 987.060393 987.060393 987.060393 ZT12-15 1152.4995454999998 1152.4995454999998 1152.4995454999998 ZT16-19 1414.1095559999999 1414.1095559999999 1414.1095559999999 ZT20-23 883.5481125 883.5481125 883.5481125