Please....help....I'm taking a statistics class involving Excel right now and I am very stumped on a question concerning a polynomial quadratic non-linear regression.

The data is as follows

Year
1990
1991
1992
1993
1994

Number of Scooters sold in 1000s (respective to years)
933
800
683
800
983

Let n= f(t) represent number of scooters sold at t years since 1990.
Arrange the data in columns (let t = 0 represent 1990) and prepare a scatter plot. Then find second degree polynomial fit to the data.

I know how to do the scatter plot and use a polynomial quadratic trend line but what I DON'T know how to do is use the formula n = f(t) with t = 0 representing 1990 to even begin graphing the scatter plot....

I appreciate any insight anyone can offer. Thank you.