condition mean min max ZT0-3 9.218496 9.218496 9.218496 ZT4-7 8.696011500000001 8.696011500000001 8.696011500000001 ZT8-11 10.7841185 10.7841185 10.7841185 ZT12-15 8.886856 8.886856 8.886856 ZT16-19 9.3628955 9.3628955 9.3628955 ZT20-23 8.790524999999999 8.790524999999999 8.790524999999999