condition mean min max ZT0-3 6.7051075 6.3484300000000005 7.061785 ZT4-7 8.569485 8.569485 8.569485 ZT8-11 10.69015 10.69015 10.69015 ZT12-15 0 0 0 ZT16-19 11.4488 11.4488 11.4488 ZT20-23 9.6597 9.6597 9.6597