condition mean min max ZT0-3 3.125218333333333 2.611885 3.958925 ZT4-7 1.606205 1.606205 1.606205 ZT8-11 7.023555 7.023555 7.023555 ZT12-15 13.975349999999999 12.7301 15.2206 ZT16-19 12.00085 12.00085 12.00085 ZT20-23 8.08759 8.08759 8.08759