condition mean min max ZT0-3 204.177058 204.177058 204.177058 ZT4-7 215.27354250000002 215.27354250000002 215.27354250000002 ZT8-11 165.60401000000002 165.60401000000002 165.60401000000002 ZT12-15 156.080918 156.080918 156.080918 ZT16-19 57.885597000000004 57.885597000000004 57.885597000000004 ZT20-23 66.36640349999999 66.36640349999999 66.36640349999999