condition mean min max ZT0-3 27.926373 27.926373 27.926373 ZT4-7 12.636316 12.636316 12.636316 ZT8-11 11.6177375 11.6177375 11.6177375 ZT12-15 17.893318 17.893318 17.893318 ZT16-19 14.461119 14.461119 14.461119 ZT20-23 14.5940995 14.5940995 14.5940995