In In Re Development of Authority of City of Harrisburg, 35 Pa. Commw. 415, 386 A.2d 1052 (Pa. Cmwlth. 1978) the Court stated the Factors which affect a trial court's determination include: the length of time between the date of the comparable agreement and the date of condemnation; fluctuation in the real estate market during that period; and changes in the character of the property over that time. Harrisburg, 386 A.2d at 1058.