试图计算月度百分比增长率

Question

我有一个包含5000行的庞大数据，并试图找到6月至8月期间每个城市的逐月增长率。我的数据是

id | host_id | Host_since | area
1    121       2017-08-31   LA
2    243       2017-08-15   SF   
3    243       2017-06-12   SF 
4    100       2017-07-13   NYC
5    300       2017-05-19   CHI
6    250       2017-07-20   MIN
7    135       2017-08-25   LA
.
.
.

我不在乎重复的host_id，我唯一想要的就是查看一个月内创建的ID总数。因此，我更正了查询，但仍然在“ OVER”附近显示错误。无法找出问题所在。不知道我在做什么错，因为查询对我来说很完美？任何帮助都会很棒。

Select strftime('%Y-%m', host_since) as month, area, 
count(id) as count,
100 * (count(id) - lag(count(id), 1) over (partition by area, 
order by strftime('%Y-%m', host_since))) / lag(count(id), 1) over 
(partition by area, order by strftime('%Y-%m', host_since))) 
as growth
from listings
where host_since between '2017-06-01' and '2017-08-31'
group by 1,2
order by 1;

SQLITE_ERROR：“结束”附近：语法错误