condition mean min max ZT0-3 174.415716 148.35427030000002 200.47716169999998 ZT4-7 96.36461549 94.58637154 98.14285944 ZT8-11 39.5987647775 26.38501712 52.812512435 ZT12-15 17.275623785 14.050219004999999 20.501028565 ZT16-19 57.776639555 45.546000335 70.007278775 ZT20-23 112.17840553250001 96.31913416500001 128.0376769