condition mean min max ZT0-3 8.322965 8.0171 8.62883 ZT4-7 8.494965 8.494965 8.494965 ZT8-11 7.165435 7.165435 7.165435 ZT12-15 0 0 0 ZT16-19 10.659755 10.659755 10.659755 ZT20-23 9.054925 9.054925 9.054925