帮我翻译几个短语 金融，经济类的

loan seasoning: indicates how long you have been on the loan : 货款历经年限

low-doc loan:Low Documentation Loans. Low Doc loans are a flexible solution for self-employed people who have income and assets, but are unable to provide the required financial statements or tax returns at the time of application.低凭证货款

the excess spread: Remaining net interest payments from the underlying assets of an asset-backed security, after all payables and expenses are covered. 收益差额/超额利差