The day after a system migration, our 30-plus days past due rate jumped from 2.1% to 3.4%, and the head of risk is worried and asks you whether credit quality has really deteriorated. You find the number of delinquent accounts only moved from 2,100 to 2,150. How would you figure out what's going on, and how would you report it?

系统迁移后第一天，30天以上逾期率从2.1%跳到3.4%，风控总监很紧张，问你是不是资产质量真的变差了。你查到逾期账户数只是从2100变成2150。你会怎么判断，怎么跟总监汇报？