condition mean min max ZT0-3 8.446746 8.446746 8.446746 ZT4-7 8.770897999999999 8.770897999999999 8.770897999999999 ZT8-11 7.925901 7.925901 7.925901 ZT12-15 9.271193 9.271193 9.271193 ZT16-19 8.0555685 8.0555685 8.0555685 ZT20-23 8.790595 8.790595 8.790595