In First Union Nat'l Bank v. Commonwealth, 867 A.2d 711 (Pa. Cmwlth.), exceptions dismissed, 885 A.2d 112 (Pa. Cmwlth. 2005), aff'd, 587 Pa. 507, 901 A.2d 981 (2006), three banks merged -- CoreStates, North Bank and South Bank. Prior to the merger, CoreStates and North Bank engaged in business in Pennsylvania; South Bank did not. In computing its average share value and the tax associated therewith, North Bank combined its six-year average value with the six-year average value of CoreStates and the post-merger value of South Bank. The Department recalculated North Bank's tax liability by including the pre-merger, six-year average value for South Bank. On appeal to this court, North Bank argued that South Bank was not an "institution" as defined by the Code because it had not engaged in business in Pennsylvania. Therefore, North Bank contended that the combination provision did not apply and it was not required to include South Bank's pre-merger, six-year average share value in calculating its tax liability. The Court, engaging purely in statutory construction, agreed. We concluded that the definition of "institution" was unambiguous, precluding the use of a six-year average which included pre-merger values where the merged bank had no prior contacts with Pennsylvania. Accordingly, the Court held that the Department erred in requiring North Bank to include South Bank's pre-merger value in calculating its average share value. In doing so, the Court specifically declined to address whether inclusion of South Bank's pre-merger book values would have violated the United States Constitution on due process and commerce clause grounds. First Union, 867 A.2d at 716 n.15.