condition mean min max ZT0-3 12.312199 12.312199 12.312199 ZT4-7 12.791553 12.791553 12.791553 ZT8-11 11.86402 11.86402 11.86402 ZT12-15 13.266849 13.266849 13.266849 ZT16-19 13.912717 13.912717 13.912717 ZT20-23 12.2806545 12.2806545 12.2806545