condition mean min max ZT0-3 16.002889 16.002889 16.002889 ZT4-7 17.026144 17.026144 17.026144 ZT8-11 15.7144615 15.7144615 15.7144615 ZT12-15 15.185865 15.185865 15.185865 ZT16-19 16.753346 16.753346 16.753346 ZT20-23 16.129316 16.129316 16.129316