Which of the following is the best measure of market risk premium in equity valuation?

		Arithmetic average market return over last 90 years - yield of the 10-year T-Bond
		Arithmetic average market return over last 10 years - yield of the 1-year T-Bill
		Geometric average market return over last 90 years - yield of the 10-year T-Bond
		Geometric average market return over last 10 years - yield of the 1-year T-Bill