English: https://twitter.com/OpenAlex_org/status/1489644301042683908

"Relevant data details fyi:

- there are about 205 million works in OpenAlex right now. - most but not all works are tagged with Concepts - concepts are not exclusive, most papers have about 10"

It's an example of a visualization of year-spanning changes to science overall such as the share of papers and authors by field.

Less output in terms of number of papers is not necessarily detrimental and can be considered a desirable change for scientific and/or societal progress of the affected field/s. Visualizations like this only offer preliminary bird's eye views that could be improved, get used only to identify potential things to investigate further or get approached entirely differently.

See the source to see what data the API returns for the used queries. Scientific disciplines are top-level OpenAlex concepts, each study has multiple topics (concepts).