Creating rows for interpolation

Dear All,
I have a dataset (on consumption) for the following years: 1980, 1985, 1992, 1996, 2004 and 2010, for 108 individual observations.

Now I want to interpolate for the missing years, i.e. 1981, 1982, 1983, 1984, 1993, etc. But the current dataset has rows for the missing years. How do one create spaces in-between the observed rows for interpolation?

Thanks,

Dapel