The following table shows average Canadian gas prices, per litre, from 1979 to 2007. 1979 1983 1987 1991 0 4 8 12 1996 17 Year Years Since 1979 Price (C/L) 21.98 45.92 47.95 57.05 58.52 70.56 74.48 2001 2003 22 24 2007 28 102.27 After performing a cubic regression, the leading coefficient, rounded to the nearest thousandth (three decimal places), is