condition mean min max ZT0-3 9.402921 9.402921 9.402921 ZT4-7 9.855255 9.855255 9.855255 ZT8-11 9.045885 9.045885 9.045885 ZT12-15 9.640184999999999 9.640184999999999 9.640184999999999 ZT16-19 9.135003000000001 9.135003000000001 9.135003000000001 ZT20-23 9.724834000000001 9.724834000000001 9.724834000000001