condition mean min max ZT0-3 10.903733 10.903733 10.903733 ZT4-7 10.167065000000001 10.167065000000001 10.167065000000001 ZT8-11 9.4010325 9.4010325 9.4010325 ZT12-15 9.2444125 9.2444125 9.2444125 ZT16-19 8.5103035 8.5103035 8.5103035 ZT20-23 9.8646925 9.8646925 9.8646925