Difference in Briefcase Pulled and Database records

Hi ODK Community,

Recently we are pulling data from Briefcase for ease of data analysis but noticed # of records pulled by it are different i.e. 3711 vs 3861 records available in the database tables.

Using Briefcase v1.9.0, is there any reason why Briefcase shows less (haven't use any date criteria for pull).

Thanks for the support.