For the UCCB payments received, the Canada Revenue Agency (CRA) should have send you an RC62 benefit statement. If you did not receive this statement, you can contact CRA or log into your My Account and view it.
Info on My Account: http://www.cra-arc.gc.ca/myaccount/
CRA contact Info: http://www.cra-arc.gc.ca/cntct/menu-eng.html