A textbook publishing company has compiled data on total annual sales of its business textbooks for the preceding eight years:

Year: $12345678$

Sales$(000)$: $37\mathrm{.}3044\mathrm{.}4047\mathrm{.}2051\mathrm{.}4054\mathrm{.}4057\mathrm{.}0061\mathrm{.}4069\mathrm{.}60$ a$-2.$ Forecast the preceding eight years, and determine the forecast errors. $($Negative answers should be indicated by a minus sign. Do not round intermediate calculations and round your final answer to $2$ decimal places.$)$

Year Sales$(000)$ Forecast Error Error$\backslash$Lambda $2$

$137\mathrm{.}30$

$12\mathrm{.}43$

$244\mathrm{.}40$

$14\mathrm{.}80$

$347\mathrm{.}20$

$27\mathrm{.}57$

$451\mathrm{.}40$

$30\mathrm{.}53$

$554\mathrm{.}40$

$32\mathrm{.}87$

$657\mathrm{.}00$

$35\mathrm{.}07$

$761\mathrm{.}40$

$37\mathrm{.}80$

$869\mathrm{.}60$

$39\mathrm{.}40$