Which data, specifically, would that be?
Ukraine's stated intercept rates are not mathematically possible, so they must be taken with a grain of salt. For example, they will claim to have shot down 60 of 70 missiles in an attack, but a separate official Ukraine statement about the same attack will say 20 targets were hit, which obviously is impossible if only 10 missiles got through. All numbers in my example are "for example" - not from a specific date/attack. This is a consistent theme in reporting on missile attacks.
In general, since the successful Ukrainian Kharkiv offensive in September of last year, Ukraine has been steadily losing back the ground it lost at the beginning of the invasion and then won back in September.
I use a Ukrainian based map (https://liveuamap.com/) for updates on the front. All data come from the Ukrainian general staff (military).
We will not know the exact numbers of casualties on either side until after the war - if ever. That being said, if the West's claims of 100-200k Russians lost were correct, either the Ukrainians are the worst fighters in the world, or the Russians are supermen. There is no way Russia could still be gaining incremental ground month after month if they had lost their entire original fighting force.
The Ukrainians are fierce fighters and brave, but they are massively outgunned - and just or more importantly - out "logisitic-ed." Russia has vastly shorter supply lines, more artillery and more ammunition. The poor Ukrainians are being ground down in a war of attrition.
The Russian missile strikes have kept roughly the same pace for months.
Russia appears to not have the same supply issues for weapons or ammo that the west has, for multiple reasons.
From my analysis, unless NATO enters the fight directly we will just continue to see Ukraine slowly destroyed militarily. Which - not just by the way - was one of the main stated goals of Russia with their invasion. Not to occupy Ukraine, but to de-militarize Ukraine. So far Russia is succeeding, albeit slower than I'm sure the expected.
