condition mean min max ZT0-3 228.703372 228.703372 228.703372 ZT4-7 237.6028405 237.6028405 237.6028405 ZT8-11 219.4141295 219.4141295 219.4141295 ZT12-15 250.00273650000003 250.00273650000003 250.00273650000003 ZT16-19 274.962826 274.962826 274.962826 ZT20-23 299.02522999999997 299.02522999999997 299.02522999999997