condition mean min max ZT0-3 277.808209 277.808209 277.808209 ZT4-7 296.6539725 296.6539725 296.6539725 ZT8-11 309.83189100000004 309.83189100000004 309.83189100000004 ZT12-15 297.965012 297.965012 297.965012 ZT16-19 293.602546 293.602546 293.602546 ZT20-23 298.450066 298.450066 298.450066