condition mean min max ZT0-3 252.661957 252.661957 252.661957 ZT4-7 176.27259850000002 176.27259850000002 176.27259850000002 ZT8-11 166.9946855 166.9946855 166.9946855 ZT12-15 166.000919 166.000919 166.000919 ZT16-19 149.028927 149.028927 149.028927 ZT20-23 122.68040450000001 122.68040450000001 122.68040450000001