condition mean min max ZT0-3 145.770518 145.770518 145.770518 ZT4-7 184.382186 184.382186 184.382186 ZT8-11 236.8542455 236.8542455 236.8542455 ZT12-15 225.9199505 225.9199505 225.9199505 ZT16-19 217.538832 217.538832 217.538832 ZT20-23 216.732368 216.732368 216.732368