select nvl(creation2016,to_date('01.01.2016','DD.MM.YYYY')),nvl(cnt_CREATED_ON,0), nvl(c17.creation2017,to_date('01.01.2017','DD.MM.YYYY')), nvl(cnt_CREATED_ON_1,0)
from
    (SELECT trunc(CREATED_ON) as creation2016 , COUNT(CREATED_ON) cnt_CREATED_ON
        FROM DS_HD_ISSUE_LIST_2017
        WHERE CREATED_ON BETWEEN /*'01.10.2015'*/sysdate - INTERVAL  '15' month AND (sysdate - INTERVAL '1' year)
        GROUP BY  trunc(CREATED_ON)
    )c16
full join
    (SELECT trunc(CREATED_ON) as creation2017 , COUNT(CREATED_ON) cnt_CREATED_ON_1
        FROM DS_HD_ISSUE_LIST_2017
        WHERE CREATED_ON BETWEEN /*'01.10.2016'*/ sysdate - INTERVAL  '3' month AND sysdate
        GROUP BY  trunc(CREATED_ON)
    )c17 on c16.creation2016 + INTERVAL  '1' year = c17.creation2017