Table:
text: Vukovar
Demographics
National structure of the population in the municipality of Vukovar:[ 
 clarification needed 
 ]
Year_of_census total Croats Serbs Others_
2001 31670 18,199 (57.46%) 10,412 (32.88%) 3,059 (9.66%)
1991 84024 36,910 (43.93%) 31,910 (37.98%) 15,204 (18.09%)
1981 81203 30,157 (37.14%) 25,146 (30.97%) 25,903 (31.89%)
1971 76602 34,629 (45.21%) 28,470 (37.17%) 13,593 (17.09%)
1961 54707 24,527 (44.83%) 22,774 (41.63%) 7,406 (13.54%)

Question: What is the average post-1971 census total of 10,412 (32.88) Serbs under Vukovar?