condition mean min max ZT0-3 10.847912 10.847912 10.847912 ZT4-7 10.696712999999999 10.696712999999999 10.696712999999999 ZT8-11 10.8872235 10.8872235 10.8872235 ZT12-15 9.5084835 9.5084835 9.5084835 ZT16-19 9.983737999999999 9.983737999999999 9.983737999999999 ZT20-23 9.3466475 9.3466475 9.3466475