condition mean min max ZT0-3 1100.424364 1100.424364 1100.424364 ZT4-7 997.738695 997.738695 997.738695 ZT8-11 960.4994569999999 960.4994569999999 960.4994569999999 ZT12-15 943.523901 943.523901 943.523901 ZT16-19 875.5758075000001 875.5758075000001 875.5758075000001 ZT20-23 735.982485 735.982485 735.982485