condition mean min max ZT0-3 19.070267 19.070267 19.070267 ZT4-7 15.585426 15.585426 15.585426 ZT8-11 25.5614135 25.5614135 25.5614135 ZT12-15 19.889644 19.889644 19.889644 ZT16-19 34.711830500000005 34.711830500000005 34.711830500000005 ZT20-23 30.443904500000002 30.443904500000002 30.443904500000002