Choose up to four. The comparisons that teach you something are between organizations of similar size doing similar work, so put a city nonprofit beside another city nonprofit rather than beside a national program.
The foundation publishes per-project tree counts by planting season rather than an annual total; season figures here are my sums of the stated per-project minimums on its projects page (2023/24 at least 105,000; 2024/25 at least 37,500; 2025/26 at least 33,300 incl. 22,600 in the Harz and 2,000 seedlings in Brazil). The only aggregate is 'more than 2 million trees since 2006 (as of 2026)'. Finances are reported on a calendar-year basis (2024 income EUR 611,892).