I recommend you take a look at Chakhmouradian (2006), which contains a useful survey of the main HFSE-bearing minerals found in carbonatites and includes a tabulation of their respective average hafnium contents and compositional ranges.
Regards
Graham
Chakhmouradian, Anton R. "High-field-strength elements in carbonatitic rocks: geochemistry, crystal chemistry and significance for constraining the sources of carbonatites." Chemical Geology 235.1 (2006): 138-160.