condition mean min max ZT0-3 23.434517 23.434517 23.434517 ZT4-7 18.789837499999997 18.789837499999997 18.789837499999997 ZT8-11 15.331707000000002 15.331707000000002 15.331707000000002 ZT12-15 20.064975 20.064975 20.064975 ZT16-19 13.6032485 13.6032485 13.6032485 ZT20-23 13.360365 13.360365 13.360365