Natural Logarithm Regression Equation

The table gives Sweden's nuclear power generation data in billions of kilowatt-hours. Let x = 5 represent 1980, x = 10 represent 1985, and so on.

Year|1980|1985|1990|1995|

Energy produced |25.3|55.8|65.2|66.5|

(a) Find a natural logarithm regression equation for the data.

(b) Predict when Sweden's nuclear power generation will reach 85 billion kilowatt-hours.

Ok, so in my calculator i have (I think) found the ln regression equation, which is Y= a+blnx

a= -20.9

b= 30.8

r^2= .93

r= .97

So the equation should be -20.9 + 30.8lnx correct?

and to predict for (b), I need to make a graph of the data, but I am unsure on how to do that, could someone help please?

Thanks a bunch!