Hi.
I am facing problem in converting my quarterly bank level data to annual data. My data set is like as following:

bank qtr Year LLP
19901 1990
19902 1990
19903 1990
19904 1990
19911 1991
19912 1991
19913 1991
19914 1991
I want to add the value of four quarter (1+2+3+4) for each year and make them annual data. Please suggest me the code, how can I process it?

Thanks.