W. Va. Code § 11-13gG-6
(b) Applicable percentage. — For the purpose of subsection (a), the applicable percentage of any property is determined under the following table:
If useful life is: The applicable percentage is:
Less than four years 0%
Four years or more but less than six years 33 1/3%
Six years or more but less than eight years 66 2/3%
Eight years or more 100%
The useful life of any property, for purposes of this section, is determined as of the date the property is first placed in service or use in this state by the taxpayer, determined in accordance with such rules and requirements the Tax Commissioner may prescribe.
(c) Cost. — For purposes of subsection (a) of this section, the cost of each property purchased for a new, or expansion of an existing, downstream natural gas manufacturing facility is determined under the following rules:
(3) Rental property. —
(B) The cost of tangible personal property acquired by written lease for a primary term of: