No pension under this part except an accidental disability pension shall be granted or paid which shall exceed the annual amount of one-seventieth of the average annual salary or compensation received by the person to whom the pension is granted during the last ten years of the person’s employment by the county, multiplied by the number of years during which the person was in the employment or service of the county; provided notwithstanding any other provisions of this part, and regardless of the computed amount, any person or widow eligible to a pension shall be granted and paid not less than $50 per month.