[R] re ferring to data of previous rows

[clion]

Dear Rlers,
in the following dataset I would like to insert a new column that refers to
the data of the previous row. 
My question is whether the probability of a female (Id) changes if she had
given birth to a pup in the previous year. So my dataframe consists of the
column Id, year (2003-2007 for each Id) and offspring (=of; 1-0):
Id   year   of      
1   2003   1      
1   2004   0      
1   2005   1      
1   2006   1      
1   2007   0      with 1= female (Id) gave birth to offspring (same year)
2   2003   0      and 0 = female didn't pup
2   2004   1      
2   2005   1      
2   2006   0      
2   2007   1      
3   2003   1      
3   2004   1      
3   2005   1      
3   2006   0      
3   2007   0      
Now I want to add the column "offspring in the previous year - yes/no(1-0)"
the output now should look like this:

Id  year   of   of_inPreviousYear
1   2003   1   NA
1   2004   0   1
1   2005   1   0
1   2006   1   1
1   2007   0   1
2   2003   0   NA
2   2004   1   0
2   2005   1   1
2   2006   0   1
2   2007   1   0
3   2003   1   NA
3   2004   1   1
3   2005   1   1
3   2006   0   1
3   2007   0   0

any idea how I could program that?

thanks a lot,
clion
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