condition mean min max ZT0-3 20.380615 20.380615 20.380615 ZT4-7 15.3009525 15.3009525 15.3009525 ZT8-11 18.815446 18.815446 18.815446 ZT12-15 17.231431 17.231431 17.231431 ZT16-19 29.7751935 29.7751935 29.7751935 ZT20-23 21.164360000000002 21.164360000000002 21.164360000000002