This is the 15782nd most frequent Russian word.
проголосовавших
"Those who voted."
In this sentence, 'проголосовавших' is used as a participle functioning as a noun, referring to people who voted.
Проголосовавших было больше, чем ожидалось.
There were more voters than expected.
In this case, 'проголосовавших' is part of a phrase indicating the group or count of individuals who voted.
Количество проголосовавших определяет исход выборов.
The number of voters determines the outcome of the election.
Here, 'проголосовавших' modifies 'список' and refers to individuals who have cast their vote.