i am trying to look back on some farm diesel fuel prices during the 2015 crop year to clear up a fuel contract with my supplier. i believe they were going off a december contract of some sort but not real sure the details on it. they say i owe them over a buck a gallon for fuel not taken delivery for, if it is true fuel went down over a dollar from jan to dec of 2015 i have no problem paying it, but could that be true it varied that much. thought maybe someone on here could help find a chart to reference. i have had no luck on google searching for it. 

its a small enough amount that i am not going to argue about it, life is too short but seriously over a dollar a gallon?