condition mean min max ZT0-3 7.820455 7.820455 7.820455 ZT4-7 7.7308185 7.7308185 7.7308185 ZT8-11 9.2296905 9.2296905 9.2296905 ZT12-15 8.3693385 8.3693385 8.3693385 ZT16-19 7.1633215 7.1633215 7.1633215 ZT20-23 8.3982375 8.3982375 8.3982375