condition mean min max ZT0-3 3.4264033333333335 1.230485 4.83373 ZT4-7 0.850557 0.850557 0.850557 ZT8-11 3.8319150000000004 3.8319150000000004 3.8319150000000004 ZT12-15 9.3039325 8.937190000000001 9.670675 ZT16-19 9.789214999999999 9.789214999999999 9.789214999999999 ZT20-23 9.44744 9.44744 9.44744