condition mean min max ZT0-3 14.454725 13.151 15.75845 ZT4-7 7.88512 7.88512 7.88512 ZT8-11 8.159985 8.159985 8.159985 ZT12-15 0 0 0 ZT16-19 9.468715 9.468715 9.468715 ZT20-23 10.9827 10.9827 10.9827