Question: What is the population within the city limits of the city where the company Sibur is headquartered ?
Sentence (from "Sibur"): SIBUR operates 26 production sites located all over Russia, had over 1,400 major customers engaged in the energy, automotive, construction, fast-moving consumer goods (FMCG), chemical and other industries in approximately 70 countries worldwide and employed around 28,000 personnel.
Relevant evidence: No