condition mean min max ZT0-3 7.667495000000001 7.667495000000001 7.667495000000001 ZT4-7 7.01295 7.01295 7.01295 ZT8-11 7.715955 7.715955 7.715955 ZT12-15 8.965340000000001 8.965340000000001 8.965340000000001 ZT16-19 10.79997 10.79997 10.79997 ZT20-23 8.29961 8.29961 8.29961