condition mean min max ZT0-3 6.00867 4.345745 7.671595 ZT4-7 13.026 13.026 13.026 ZT8-11 17.45745 17.45745 17.45745 ZT12-15 0 0 0 ZT16-19 18.18325 18.18325 18.18325 ZT20-23 11.41272 11.41272 11.41272