请阅读下面这张Markdown格式的表格并回答问题。同一行中不同列的单元格用'|'分隔，不同行的单元格用'
'分隔。

表格标题:
92 表18：福州住宅期房2007-2012年1月各月成交面积（万平）           
表格:
| 时间 | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
| --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
| 2008.0 | 16.0 | 12.0 | 12.0 | 8.0 | 13.0 | 15.0 | 17.0 | 14.0 | 17.0 | 12.0 | 20.0 | 27.0 |
| 2009.0 | 48.0 | 33.0 | 44.0 | 52.0 | 56.0 | 57.0 | 64.0 | 29.0 | 35.0 | 41.0 | 49.0 | 54.0 |
| 2010.0 | 26.0 | 14.0 | 19.0 | 26.0 | 9.0 | 8.0 | 9.0 | 14.0 | 19.0 | 30.0 | 16.0 | 15.0 |
| 2011.0 | 20.0 | 12.0 | 19.0 | 15.0 | 14.0 | 27.0 | 17.0 | 14.0 | 10.0 | 11.0 | 10.0 | 8.0 |
问题:
福州住宅期房五月成交均值为多少啊，已知三月或者四月的成交面积都是大于20万平的
Answer:
32.5