Assuming data such as the following:

```
  ID      EffDate            Rate
   1      12/12/2011         100
   1      01/01/2012         110
   1      02/01/2012         120
   2      01/01/2012          40
   2      02/01/2012          50
   3      01/01/2012          25
   3      03/01/2012          30
   3      05/01/2012          35

```

How would I find the rate for ID 2 as of 1/15/2012?
Or, the rate for ID 1 for 1/15/2012?

In other words, how do I do a query that finds the correct rate when the date falls between the EffDate for two records? (Rate should be for the date prior to the selected date).

Thanks,
John