select field with numeric key doesn't work

If I create a selectfield on tax value containing ‘high’, ‘low’ and ‘zero’ and have the taxrates of 19.00 11.00 and 0.00 as key which needs to be stored in the database then the value will be stored. But on retrieval the value from the database is not displayed in the field. Instead the ‘select’ text is show.

table tax

rate(key) description
0.00 zero

table activity

fields …
tax number(6,2)

Hello Albert,

Is the decimal field your table primary key?

regards,
Bernhard