condition mean min max ZT0-3 313.968569 313.968569 313.968569 ZT4-7 304.83957799999996 304.83957799999996 304.83957799999996 ZT8-11 326.574616 326.574616 326.574616 ZT12-15 326.4242865 326.4242865 326.4242865 ZT16-19 325.8963745 325.8963745 325.8963745 ZT20-23 332.584528 332.584528 332.584528