condition mean min max ZT0-3 19.098716666666668 12.0265 22.7228 ZT4-7 19.5461 19.5461 19.5461 ZT8-11 29.82445 29.82445 29.82445 ZT12-15 52.100525000000005 48.96855 55.2325 ZT16-19 38.637100000000004 38.637100000000004 38.637100000000004 ZT20-23 38.917 38.917 38.917