Rating is going to be a number (didn't actually check, so could be wrong), so your expressions should be more like
<%if Rating >= 0 and Rating < 1%>
<%elsif Rating >= 1 and Rating < 2%>*
<%elsif Rating >= 2 and Rating < 3%>**
...
Adrian
<%if Rating >= 0 and Rating < 1%>
<%elsif Rating >= 1 and Rating < 2%>*
<%elsif Rating >= 2 and Rating < 3%>**
...
Adrian