condition mean min max ZT0-3 12.821172 12.821172 12.821172 ZT4-7 13.4436715 13.4436715 13.4436715 ZT8-11 13.150891999999999 13.150891999999999 13.150891999999999 ZT12-15 11.4554845 11.4554845 11.4554845 ZT16-19 13.87061 13.87061 13.87061 ZT20-23 11.8489425 11.8489425 11.8489425