In this paper, we present our contribution in SemEval-2020 Task 1: Unsupervised Lexical Semantic Change Detection, where we systematically combine existing models for unsupervised capturing of lexical semantic change across time in text corpora of German, English, Latin and Swedish.In particular, we analyze the score distribution of existing models. Then we define a general classification threshold, adjust it independently to each of the models and measure the models' score certainty. Finally, using both the threshold and score certainty, we aggregate the models for the two sub-tasks: binary classification and ranking.