The most "Eastern" cities of Poland in terms of population

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Percent of people from the Soviet Union (= Former Eastern Poland) in each city according to the 1950 census:

Opole - 45.69%
Brzeg - 40.28%
Gorzów Wlkp. - 39.92%
Olsztyn - 38.54%
Legnica - 37.18%
Słupsk - 34.50%
Koszalin - 30.56%
Zielona Góra - 29.74%
Wrocław - 29.20%
Jelenia Góra - 28.10%
Nysa - 26.33%
Gliwice - 25.11%
Świdnica - 22.47%
Szczecin - 21.52%
Gdańsk - 21.34%
Piła - 20.67%
Wałbrzych - 18.20%
Elbląg - 17.56%
Sopot - 16.52%
Bytom - 16.09%
Racibórz - 6.82%
Zabrze - 5.99%

Number of people from the Soviet Union (= Former Eastern Poland) in each city according to the 1950 census:

Wrocław - 90211
Gdańsk - 41544
Szczecin - 38493
Gliwice - 30129
Bytom - 27984
Opole - 17574
Wałbrzych - 17081
Olsztyn - 16894
Legnica - 14505
Gorzów Wlkp. - 13103
Słupsk - 11425
Zabrze - 10323
Jelenia Góra - 9833
Zielona Góra - 9409
Elbląg - 8447
Świdnica - 6249
Sopot - 6065
Koszalin - 5788
Brzeg - 5144
Piła - 4359
Nysa - 4006
Racibórz - 1803

Of course since 1950 proportions could change, however no more recent data about this is available, AFAIK.

 

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Map showing percentages of Poles from Kresy in each city in 1950:

 

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And compared to overall percentage of people from Kresy in each region:

 

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And here the list of counties which had an even higher percent of Poles from Kresy than the city of Opole:

Oława - 67.03%
Głubczyce - 60.91%
Góra - 59.54%
Wołów - 58.76%
Sulęcin - 57.94%
Lwówek - 57.22%
Świebodzin - 56.11%
Chojna - 55.98%
Lubin - 55.18%
Rzepin - 53.50%
Strzelin - 52.27%
Wrocławski - 51.29%
Niemodlin - 50.06%
Gubin - 46.96%
Legnica - 46.60%
Lubań - 46.34%
Środa Śląska - 45.81%
Wschowa - 45.75%