Are there any numbers (estimates) for how many anime shows have been adapted from manga, light novels, visual novels, and games?

Databases like myanimelist or anisearch often include the original source for each entry.
The second database also allows us to filter the entries based on the source type so we can get some numbers.
The following are rough estimates when we only consider series (overall about 4700):

• Based on manga: 1620
• Based on light novel: 400
• Based on video game: 280
• Based on visual novel: 160
• Original works: 880

Not included are adaptations from other media like comics, manhua, manwha or other anime.