condition mean min max ZT0-3 83.983321 83.983321 83.983321 ZT4-7 124.47772 124.47772 124.47772 ZT8-11 129.4249545 129.4249545 129.4249545 ZT12-15 141.149176 141.149176 141.149176 ZT16-19 213.0217715 213.0217715 213.0217715 ZT20-23 250.0281725 250.0281725 250.0281725