condition mean min max ZT0-3 8.516085 8.1632 8.868970000000001 ZT4-7 10.07469 10.07469 10.07469 ZT8-11 11.20279 11.20279 11.20279 ZT12-15 16.85931875 13.7248375 19.9938 ZT16-19 14.968498333333333 12.37693 17.560066666666668 ZT20-23 0 0 0