How to get the R2 value of fit?

In the code below, how to output the R2 value of the fitted coefficients?

ft = fittype('b*x^2+c*x+a');
load enso
fit(month,pressure,ft,'StartPoint',[1,3,5])

Answer 1

[Stephan]

ft = fittype('b*x^2+c*x+a');
load enso
[curve, gof]=fit(month,pressure,ft,'StartPoint',[1,3,5])