condition mean min max ZT0-3 11.292703 11.292703 11.292703 ZT4-7 9.4429725 9.4429725 9.4429725 ZT8-11 9.389191 9.389191 9.389191 ZT12-15 10.050813000000002 10.050813000000002 10.050813000000002 ZT16-19 9.4609485 9.4609485 9.4609485 ZT20-23 8.826399 8.826399 8.826399