Please help

Hello, I just came across this data (on prof. Labov's page).
What does it mean and how can I interpretate this ?
Many thanks.

''Mean F1 of the stressed vowel in study, mother, bud, just by dialect:



Pittsburgh--------------787
Eastern New England--768
RP------------------------754
Atlantic Provinces------746
Providence--------------736
Canada------------------736
Cincinnati--------------730
Western New England-728
Boston----------------- 727
St. Louis---------------726
Western Pennsylvania-725
Florida-----------------723
Middle Atlantic---------721
West--------------------712
Charleston--------------712
Inland North------------706
North-------------------701.4
Midland-----------------695
NYC---------------------692
South-------------------687
Texas South------------673
Inland South-----------664 ''

This is referring to phonetic analysis data. F1 refers to frequency one. The higher the number for F1, the lower that sound is produced in the mouth. Thus what these data show is that of the areas surveyed, in Pittsburgh the sound in "bud" is produced lowest in the mouth while it's produced highest in the mouth in the Inland South.

This chart doesn't show data for F2, but that frequency shows how front or back in the mouth a certain vowel is. Once you know both F1 and F2 values you can have a good idea of where a vowel is produced in the mouth. Thus, /i/ is going to have a low F1 and high F2 value while /A/ has a high F1 and low F2 value.

If you wish to know your own frequencies for any given vowel you can download a freeware phonetic program such as Praat or Wavesurfer.