condition mean min max ZT0-3 37.88901 37.88901 37.88901 ZT4-7 44.567379 44.567379 44.567379 ZT8-11 20.379078 20.379078 20.379078 ZT12-15 15.442263 15.442263 15.442263 ZT16-19 12.971951 12.971951 12.971951 ZT20-23 10.394271 10.394271 10.394271