our refining and wholesale marketing gross margin is the difference between the prices of refined products sold and the costs of crude oil and other charge and blendstocks refined , including the costs to transport these inputs to our refineries , the costs of purchased products and manufacturing expenses , including depreciation . the crack spread is a measure of the difference between market prices for refined products and crude oil , commonly used by the industry as an indicator of the impact of price on the refining margin . crack spreads can fluctuate significantly , particularly when prices of refined products do not move in the same relationship as the cost of crude oil . as a performance benchmark and a comparison with other industry participants , we calculate midwest ( chicago ) and u.s . gulf coast crack spreads that we feel most closely track our operations and slate of products . posted light louisiana sweet ( 201clls 201d ) prices and a 6-3-2-1 ratio of products ( 6 barrels of crude oil producing 3 barrels of gasoline , 2 barrels of distillate and 1 barrel of residual fuel ) are used for the crack spread calculation . the following table lists calculated average crack spreads by quarter for the midwest ( chicago ) and gulf coast markets in 2008 . crack spreads ( dollars per barrel ) 1st qtr 2nd qtr 3rd qtr 4th qtr 2008 .
how much higher was the u.s gulf coast crack spread than the chicago crack spread in the first quarter of 2008?
in addition to the market changes indicated by the crack spreads , our refining and wholesale marketing gross margin is impacted by factors such as the types of crude oil and other charge and blendstocks processed , the selling prices realized for refined products , the impact of commodity derivative instruments used to mitigate price risk and the cost of purchased products for resale . we process significant amounts of sour crude oil which can enhance our profitability compared to certain of our competitors , as sour crude oil typically can be purchased at a discount to sweet crude oil . finally , our refining and wholesale marketing gross margin is impacted by changes in manufacturing costs , which are primarily driven by the level of maintenance activities at the refineries and the price of purchased natural gas used for plant fuel . our 2008 refining and wholesale marketing gross margin was the key driver of the 43 percent decrease in rm&t segment income when compared to 2007 . our average refining and wholesale marketing gross margin per gallon decreased 37 percent , to 11.66 cents in 2008 from 18.48 cents in 2007 , primarily due to the significant and rapid increases in crude oil prices early in 2008 and lagging wholesale price realizations . our retail marketing gross margin for gasoline and distillates , which is the difference between the ultimate price paid by consumers and the cost of refined products , including secondary transportation and consumer excise taxes , also impacts rm&t segment profitability . while on average demand has been increasing for several years , there are numerous factors including local competition , seasonal demand fluctuations , the available wholesale supply , the level of economic activity in our marketing areas and weather conditions that impact gasoline and distillate demand throughout the year . in 2008 , demand began to drop due to the combination of significant increases in retail petroleum prices and a broad slowdown in general activity . the gross margin on merchandise sold at retail outlets has historically been more constant . the profitability of our pipeline transportation operations is primarily dependent on the volumes shipped through our crude oil and refined products pipelines . the volume of crude oil that we transport is directly affected by the supply of , and refiner demand for , crude oil in the markets served directly by our crude oil pipelines . key factors in this supply and demand balance are the production levels of crude oil by producers , the availability and cost of alternative modes of transportation , and refinery and transportation system maintenance levels . the volume of refined products that we transport is directly affected by the production levels of , and user demand for , refined products in the markets served by our refined product pipelines . in most of our markets , demand for gasoline peaks during the summer and declines during the fall and winter months , whereas distillate demand is more ratable throughout the year . as with crude oil , other transportation alternatives and system maintenance levels influence refined product movements . integrated gas our integrated gas strategy is to link stranded natural gas resources with areas where a supply gap is emerging due to declining production and growing demand . our integrated gas operations include marketing and transportation of products manufactured from natural gas , such as lng and methanol , primarily in the u.s. , europe and west africa . our most significant lng investment is our 60 percent ownership in a production facility in equatorial guinea , which sells lng under a long-term contract at prices tied to henry hub natural gas prices . in 2008 , its .