Found this interesting chart on aircraft production figures for all types for 1939 to 45, apparently from the WW2 Almanac or something, no idea of accuracy but they seem reasonable enough to me and seem to match what I have already heard.
The US seriously kicked into gea, going from lowest here by far in 1939, to tripling production by 1940, then tripling again from '40 to '41, then more than doubling from '41 to '42, almost doubling again from '42 to '43, finally levelling off a bit in '44 and then backing off in '45 obviosuly as the war wound down. You can see the massive industrial might they had at the time, noone else comes close.
US
1939 - 2,141
1940 - 6,086
1941 - 19,433
1942 - 47,836
1943 - 85,898
1944 - 96,318
1945 - 46,001
Total - 303,713
Britain was already cranking them out in 1939 when the war officially started, almost doubling in 1940 during the Battle of Britain, but then only adding a bit each year until they pretty much topped out in 1943/44 at 26K per year, maybe this was their upper limit of production?
Britain
1939 - 7,940
1940 - 15,049
1941 - 20,094
1942 - 23,672
1943 - 26,263
1944 - 26,461
1945 - 12,070
Total - 131,549
The USSR was obviously preparing for a war in '39, 10K per year in 1939 is easily the most aircraft of this lot, only Germany comes close at the time. They seemed to have kept up and even increased production during the early invasion years when they were shfiting production to the urals, then they shifted gear and got into it, though never really made that many compared to the US for example. their peak production in 1944 was not even as much as Germany, though I guess they didn't need so many as they were also being given lots of aircraft via lend lease
USSR
1939 - 10,382
1940 - 10,565
1941 - 15,737
1942 - 25,436
1943 - 34,900
1944 - 40,300
1945 - 20,900
Total - 158,220
Germany was unsuprisingly at fairly high production (comparatively) in '39, suprisingly not increasing production all that much until the later years, you can see them creeing up quite a bit in '43 then a lot in '44, but then of course dropping off considerably in '45 for obvious reasons.
Germany
1939 - 8,295
1940 - 10,826
1941 - 12,401
1942 - 15,409
1943 - 24,807
1944 - 40,593
1945 - 7,540
Total - 119,871
Suprisingly Japans output is quite low, even in the first 3 years when they were quite involved in war on all fronts, even by '42 they are still at quite low production, they start pedalling harder in '43 once they realise they are starting to lose ground, then hitting full speed in '44 like Germany when they probably realise they might in fact lose, then petering out in '45 once they did lose.
Japan
1939 - 4,467
1940 - 4,768
1941 - 5,088
1942 - 8,861
1943 - 16,693
1944 - 28,180
1945 - 8,263
Total - 76,320
Quite interesting really, why didn't Germany or Japan increase production until the later years? Was it overconfidence in victory? or does it take until you are getting hammered and your homeland is under threat to realise you need to pull your finger out? Or was it due to mounting losses that production needed to be upped?