condition mean min max ZT0-3 1232.0 1232.0 1232.0 ZT4-7 1284.2 1284.2 1284.2 ZT8-11 1191.85 1191.85 1191.85 ZT12-15 1329.25 1329.25 1329.25 ZT16-19 1531.5500000000002 1531.5500000000002 1531.5500000000002 ZT20-23 1516.35 1516.35 1516.35