LogCLI should let you do that. From the docs
You can download an unlimited number of logs in parallel, there are a few flags which control this behaviour:
--parallel-duration
--parallel-max-workers
--part-path-prefix
--overwrite-completed-parts
--merge-parts
--keep-parts
Depending on what sort of reporting you want to do, you might be able to use metrics queries to summarise things. A whole year of data is probably a bit much to try to graph, but per week or per month summaries might work.