condition mean min max ZT0-3 10.7378675 9.972864999999999 11.50287 ZT4-7 9.324305 9.324305 9.324305 ZT8-11 9.737245 9.737245 9.737245 ZT12-15 0 0 0 ZT16-19 14.7458 14.7458 14.7458 ZT20-23 11.9569 11.9569 11.9569