No such license shall be issued to a mutual insurance company which charges a full cash premium, unless it has applications for insurance aggregating not less than $500,000 in not less than 200 separate risks, upon which it shall have received in cash at least one premium for a term not less than one year, amounting in the aggregate to at least $10,000; provided, that this requirement shall not apply to a mutual insurance company having a fully paid up guaranty capital of not less than $500,000, nor to mutual life insurance companies, nor to mutual employers’ liability insurance companies.