39-22-303(8)
For tax years beginning on or after Jan. 1, 1986, corporations are not includible in a combined report if eighty percent or more of the property and payroll are assigned to locations outside the United States. The eighty percent threshold is determined by averaging the property and payroll factors. The property and payroll factors shall be determined in accordance with section 24-60-1301, C.R.S. and all rules thereunder.