The total amount of consumer credit has been increasing steadily in recent years. The following table gives the total outstanding consumer credit $($in billions of dollars$).$ Answer parts $($a$)$ through $($e$)$ below.

$\backslash$table$[[$Year$,\backslash$table$[[$Consumer$],[$Credit$]],$Year,$\backslash$table$[[$Consumer$],[$Credit$]]],[2004,2250\mathrm{.}5,2009,2553\mathrm{.}5],[2005,2350\mathrm{.}8,2010,2648\mathrm{.}1],[2006,2465\mathrm{.}0,2011,2756\mathrm{.}0],[2007,2540\mathrm{.}9,2012,2928\mathrm{.}3],[2008,2597\mathrm{.}1,2013,3097\mathrm{.}2]]$

a$.$ Find an equation for the least squares line, letting $x$ equal the number of years since $2000$

The equation is $Y=Nx+$

$($Use integers or decimals for any numbers in the equation. Round to two decimal places as needed.$)$