condition mean min max ZT0-3 1.304616 1.253882 1.35535 ZT4-7 1.2296865 1.2296865 1.2296865 ZT8-11 5.625715 5.625715 5.625715 ZT12-15 0 0 0 ZT16-19 5.19917 5.19917 5.19917 ZT20-23 2.204485 2.204485 2.204485