condition mean min max ZT0-3 195.469923 195.469923 195.469923 ZT4-7 259.8474415 259.8474415 259.8474415 ZT8-11 241.847441 241.847441 241.847441 ZT12-15 200.63859200000002 200.63859200000002 200.63859200000002 ZT16-19 131.343291 131.343291 131.343291 ZT20-23 77.06655549999999 77.06655549999999 77.06655549999999