condition mean min max ZT0-3 13.0236275 12.005605 14.04165 ZT4-7 6.62405 6.62405 6.62405 ZT8-11 5.204795000000001 5.204795000000001 5.204795000000001 ZT12-15 0 0 0 ZT16-19 9.108385 9.108385 9.108385 ZT20-23 9.0382 9.0382 9.0382