One xAPI statement is about one kilobyte, on average. So, for the Veracity Learning plans, you can estimate the limit on the total xAPI statement count from the storage volume limit for each plan:
Plan
Storage
xAPI Statements
Free
100MB
50K–100K
Starter
1GB
100K–1M
Pro
5GB
1M–5M
Expert
30GB
5M–30M
Enterprise
Varies (based on your infrastructure)
However, the size of an xAPI statement depends on the learning record provider, if the statement includes attachments, and other factors.