JOIN Usage

[Sean S]

I'm stumped...

I have two tables that look like this...

Table Name: Dispositions
+---------------+------+--------------------------+
| DispositionID | Code | Disposition |
+---------------+------+--------------------------+
| 1 | 278 | Strong |
| 2 | NULL | Refused Treat./Transp. |
| 3 | 272 | Highland |
| 4 | 273 | Lakeside |
| 5 | 275 | Park Ridge |
| 6 | 276 | RGH |
| 7 | 277 | St. Mary's |
| 9 | NULL | Nursing home |
| 10 | NULL | Other med. Facility |
| 11 | NULL | Residence |
| 12 | NULL | Transfer Care to Other |
| 13 | NULL | Call Cancelled |
| 14 | NULL | Standby |
| 15 | NULL | No patient found |
| 16 | NULL | Other |
| 17 | NULL | Police/Jail |
| 18 | NULL | Morgue |
| 19 | NULL | Provided Care with Other |
+---------------+------+--------------------------+

...and...

Table Name: Calls
+--------+------------+---------------+
| CallID | Date | dispositionID |
+--------+------------+---------------+
| 1856 | 2005-04-16 | 1 |
| 1857 | 2005-04-16 | 1 |
| 1858 | 2005-04-16 | 1 |
| 1859 | 2005-04-17 | 2 |
| 1860 | 2005-04-17 | 2 |
| 1862 | 2005-04-18 | 1 |
| 1863 | 2005-04-18 | 12 |
| 1864 | 2005-04-18 | 15 |
| 1865 | 2005-04-18 | 1 |
| 1866 | 2005-04-18 | 1 |
| 1867 | 2005-04-19 | 1 |
| 1868 | 2005-04-19 | 14 |
| 1869 | 2005-04-19 | 12 |
| 1870 | 2005-04-19 | 2 |
| 1871 | 2005-04-21 | 1 |
| 1872 | 2005-04-21 | 14 |
| 1873 | 2005-04-21 | 1 |
| 1874 | 2005-04-22 | 1 |
| 1875 | 2005-04-22 | 2 |
| 1876 | 2005-04-22 | 14 |
| 1877 | 2005-04-22 | 14 |
| 1878 | 2005-04-22 | 1 |
| 1879 | 2005-04-22 | 1 |
| 1880 | 2005-04-23 | 1 |
| 1881 | 2005-04-23 | 2 |
| 1882 | 2005-04-23 | 1 |
| 1883 | 2005-04-24 | 2 |
| 1884 | 2005-04-25 | 1 |
| 1885 | 2005-04-25 | 1 |
| 1886 | 2005-04-25 | 1 |
+--------+------------+---------------+

I want to write a SELECT statement that returns all of the dispositions and counts those that match. So I'd like to end up with something like...
Strong 15
Refused Treat./Transp. 10
Highland 2
Lakeside 0
Park Ridge 3
RGH 5
St. Mary's 0
Nursing home 0
Other med. Facility 0
Residence 0
Transfer Care to Other 6
Call Cancelled 6
Standby 10
No patient found 1
Other 1
Police/Jail 0
Morgue 0
Provided Care with Other 0

I have come up with this,
SELECT
Dispositions.Disposition,
Dispositions.dispositionID,
COUNT(Calls.dispositionID) AS DispositionCount
FROM Dispositions
LEFT JOIN Calls ON Dispositions.dispositionID = Calls.dispositionID
WHERE Calls.date > '2005-03-31'
AND Calls.date < '2005-05-01'
AND ( Calls.ambulanceID IS NOT NULL
OR Calls.dispositionID = '2'
OR Calls.dispositionID = '12' )
GROUP BY Calls.dispositionID
ORDER BY Dispositions.Disposition

But that only provides,
+------------------------+---------------+------------------+
| Disposition | dispositionID | DispositionCount |
+------------------------+---------------+------------------+
| Call Cancelled | 13 | 3 |
| Highland | 3 | 3 |
| Other | 16 | 1 |
| Refused Treat./Transp. | 2 | 21 |
| Standby | 14 | 7 |
| Strong | 1 | 27 |
| Transfer Care to Other | 12 | 3 |
+------------------------+---------------+------------------+

Any help would be greatly appreciated. Thanks.
-Sean