condition mean min max ZT0-3 28.30774656 24.90740572 31.7080874 ZT4-7 13.61304372825 11.4838664615 15.742220995 ZT8-11 12.25223154475 11.8363427295 12.66812036 ZT12-15 10.8927171565 10.4322371 11.353197213 ZT16-19 14.092080540000001 12.89754757 15.28661351 ZT20-23 18.567890452500002 17.630117615000003 19.50566329