Demand for video projectors from a reputed company over the last two years is shown in Table $2.$ The company is trying to forecast the demand for the year of $2022.$

Table $2$: Monthly Demand for Video Projectors

Month

Demand

Month

Demand

Jan$-20$

$120$

Jan$-21$

$118$

Feb$-20$

$105$

Feb$-21$

$110$

Mar$-20$

$97$

Mar$-21$

$95$

Apr$-20$

$85$

Apr$-21$

$90$

May$-20$

$98$

May$-21$

$100$

Jun$-20$

$110$

Jun$-21$

$115$

Jul$-20$

$125$

Jul$-21$

$122$

Aug$-20$

$102$

Aug$-21$

$98$

Sep$-20$

$92$

Sep$-21$

$88$

Oct$-20$

$90$

Oct$-21$

$79$

Nov$-20$

$100$

Nov$-21$

$95$

Dec$-20$

$115$

Dec$-21$

$110$

$($a$)$ Plot the demand data and comment on the pattern. What should be the most appropriate method to forecast demand for $2022?$