Hello, sorry if the title is not clear! A small sample of my data can be seen below. My aim is to delete all rows from a certain company (TICKER) if they do not have observations from all years 2010-2020. For example, in the data below, I would keep all the rows for ticker A, however since AAA and AAAP only have data for some years I would want to drop all the rows for those tickers. I have tried to play around with the DROP IF function however I am new to Stata so I'm also having difficulties finding search terms for help on what I'm looking for. Sorry since this has probably been answered previously.

Code:
TICKER    year    RET
A    2010    .360587924
A    2011    -.105289804
A    2012    .200218003
A    2013    .368424385
A    2014    .002363122
A    2015    .065968707
A    2016    .119250455
A    2017    .40943002
A    2018    .040816839
A    2019    .279583614
A    2020    .367221266
AA    2010    .055579704
AA    2011    -.490790864
AA    2012    .041280666
AA    2013    .237985016
AA    2014    .427898743
AA    2015    -.425617623
AA    2016    .055984234
AA    2017    .764060466
AA    2018    -.64663515
AA    2019    -.139412225
AA    2020    .646594437
AAA    2020    .007631533
AAAP    2015    .182677761
AAAP    2016    -.033216692
AAAP    2017    1.2492474
AAAP    2018    -.014702334