condition mean min max ZT0-3 2.1847725000000002 1.889125 2.48042 ZT4-7 2.23209 2.23209 2.23209 ZT8-11 2.67375 2.67375 2.67375 ZT12-15 0 0 0 ZT16-19 2.1107299999999998 2.1107299999999998 2.1107299999999998 ZT20-23 2.97157 2.97157 2.97157