The data file Births Australia shows annual observations on the first confinement resulting in a live birth

Question:

The data file Births Australia shows annual observations on the first confinement resulting in a live birth of the current marriage (Y) and the number of first marriages (for females) in the previous year (X) in Australia. Estimate the model (McDonald 1981)
yt = β0 + β1xt + γyt-1 + εt
and write a report on your findings.