Use the monthly data (September 2013 - November 2014) provided on the closing prices for Gold (GLD), NASDAQ, Oil (USO) and Facebook (FB). Date GLD NASDAQ USO FB Sep-13 128 3771 37 50 Oct-13 128 3920 35 50 Nov-13 121 4060 33 47 Dec-13 116 4177 35 55 Jan-14 120 4104 35 63 Feb-14 128 4308 37 68 Mar-14 124 4199 37 60 Apr-14 124 4115 36 60 May-14 120 4243 38 63 Jun-14 128 4408 39 67 Jul-14 123 4370 36 73 Aug-14 124 4580 36 75 Sep-14 116 4493 34 79 Oct-14 113 4631 31 75 Nov-14 115 4713 29 74 What is the mean monthly return for Oil during the sample period? -0.68% -1.60% 1.64% 3.12%