每个月的Mysql计数

Question

我有一个 mysql 表，看起来像这样：

id      level      time
1         1     2014-02-19 04:33:04
2         1     2014-03-19 04:33:04
3         1     2014-03-20 04:33:04
4         2     2014-03-21 04:53:04
5         1     2014-07-19 04:33:04
6         2     2014-07-19 04:33:04
7         1     2014-07-19 04:33:04
8         1     2014-08-19 04:33:04

我想像这样获得 1 级的结果：

level1count    year    month
  0            2014      1
  1            2014      2
  2            2014      3
  0            2014      4
  0            2014      5
  0            2014      6
  2            2014      7
  1            2014      8
  0            2014      9
  0            2014      10
  0            2014      11
  0            2014      12

我试过这个查询，但没有给出每个月的结果

SELECT YEAR(time) AS year, MONTH(time) AS month, COUNT(DISTINCT id) AS count FROM users where level = '1' GROUP BY year, month