Note: This is from last year. The numbers are much higher now. Ukraine puts the number of dead Russian soldiers at 376,030. The US says it's 315,000 personnel.
Either way, if those numbers are anywhere close to the trugh, then Russia has already lost ~50% of the personnel that the entire Soviet Union lost in its 9 year-long invasion of Afghanistan. And the fallout of the war in Afghanistan contributed a lot to the fall of the Soviet Union.
I ddg russian population 2023 and got this from world-o-meter:
"9th Russia 144,444,359(estimated population) -0.19%(change) -268,955(net)"
Until they have to mobilize the more dense populated area, it's just a number game for them I guess.
Oh, and compare to Ukraine, it's pretty dark.
"41th Ukraine 36,744,634 -7.45 % -2,957,105" in the later column, Migrant listed as 1,784,718 assuming fled the war. so should be part of that -2.9m decline number. I don't know what happened to the other 1.2m.