condition mean min max ZT0-3 4.5989249999999995 4.556165 4.641685 ZT4-7 8.117265 8.117265 8.117265 ZT8-11 13.34985 13.34985 13.34985 ZT12-15 0 0 0 ZT16-19 15.11935 15.11935 15.11935 ZT20-23 16.0599 16.0599 16.0599