I have a query which displays all matching reports for the last day of the month (i.e. full month reports)

```
SELECT  id, 
    DATE_FORMAT( start_date,  '%e-%b-%y' ) AS start_date, 
    DATE_FORMAT( end_date,  '%e-%b-%y' ) AS end_date, 
    DATE_FORMAT( end_date,  '%M %Y' ) as report_month
FROM Reports
WHERE customer_id ='2321'
  AND end_of_month_file = '1'

```

Problem is duplicates - some files have been processed more than once... 

```
id start_date  end_date   report_month
1  1-Feb-14    28-Feb-14  February 2014
2  1-Mar-14    31-Mar-14  March 2014
3  1-Mar-14    31-Mar-14  March 2014
4  1-Mar-14    31-Mar-14  March 2014
5  1-Mar-14    31-Mar-14  March 2014
6  1-Mar-14    31-Mar-14  March 2014
7  1-Mar-14    31-Mar-14  March 2014
8  1-Mar-14    31-Mar-14  March 2014
9  1-Mar-14    31-Mar-14  March 2014

```

how can I filter the results to just give me the last one/latest entry for each month?