condition mean min max ZT0-3 7.427255 7.40751 7.446999999999999 ZT4-7 9.770515 9.770515 9.770515 ZT8-11 10.36075 10.36075 10.36075 ZT12-15 0 0 0 ZT16-19 11.3343 11.3343 11.3343 ZT20-23 9.347059999999999 9.347059999999999 9.347059999999999