condition mean min max ZT0-3 19.588271 19.588271 19.588271 ZT4-7 20.90992 20.90992 20.90992 ZT8-11 23.362054 23.362054 23.362054 ZT12-15 19.095740499999998 19.095740499999998 19.095740499999998 ZT16-19 19.825386 19.825386 19.825386 ZT20-23 18.73209 18.73209 18.73209