Excel - Match two columns, add value from third column and also append the unmatched data
<p>I have data in 2 tables. Both data tables have same field names since it contains billing of customers over 2 years. I need to create one table where I can compare past and current year. Hence first I need to match data of say 2016 with 2015 and get values from 2015 table in 2016. Also I need to append the unmatched values (those unmatched customers probably didn't do any billing in the current or past year). I was able to match and get values using vlookup but I culdn't append unmatched values (whose Ids are in the system but didn't do billing). Can anyone help?
Thank you.</p>

<p><a href="http://i.stack.imgur.com/kwlxH.png" rel="nofollow">Table 1</a><br>
<a href="http://i.stack.imgur.com/1orpE.png" rel="nofollow">Table 2</a><br>
<a href="http://i.stack.imgur.com/PzSFn.png" rel="nofollow">Table 3</a></p>