The height of a fence shall be measured from arterial grade, or the original grade of the property, whichever is higher and shall not exceed six feet for constructed fences and eight feet for living fences; provided, however, the permitted height along 84th Avenue N.E., N.E. 12th Street and State Route 520 shall be eight feet from arterial grade or original grade of the property, whichever is higher, for a constructed fence, and 10 feet for a living fence; provided further, that fences along 84th Avenue N.E., N.E. 12th Street and State Route 520 shall not be subject to the two-foot setback requirement as provided in CHMC § 17.37.020(C) as it now exists or may hereafter be amended. Arterial grade or original grade contours as provided in this subsection shall be followed in determining the height of the fence.