condition mean min max ZT0-3 687.739372 687.739372 687.739372 ZT4-7 1955.652534 1955.652534 1955.652534 ZT8-11 2428.596345 2428.596345 2428.596345 ZT12-15 2076.311698 2076.311698 2076.311698 ZT16-19 1379.0474474999999 1379.0474474999999 1379.0474474999999 ZT20-23 937.4180285 937.4180285 937.4180285