This is stated in the summary from the General Staff of the Armed Forces of Ukraine.
In addition to personnel, the Russians are losing their military equipment and armaments. Specifically:
On February 25, President Volodymyr Zelensky first announced the losses of the Ukrainian army: according to him, over two years of full-scale war, 31,000 Ukrainian soldiers have died. He did not disclose the number of wounded to keep the Russians unaware of how many personnel Ukraine has on the battlefield.
Previously, Kyiv had not disclosed information about losses among its servicemen. The Ministry of Defense stated that the information regarding the number of deceased Ukrainian fighters would remain classified until the end of martial law.
According to the calculations of the "Book of Memory of the Fallen for Ukraine" project, released in mid-November 2023, at least 30,000 Ukrainian fighters have died since February 24, 2022. Additionally, up to 100,000 military personnel have been injured, but most of them are still in service or will return shortly.