On January 1st of each year if the taxes, levies and assessments made the previous year shall not have been paid, one-half thereof shall become delinquent and on July 1st following if not paid, the remaining one-half of said taxes, assessments and levies shall become delinquent and such taxes, assessments and levies from the respective dates of delinquency shall bear interest at the rate of one percent per month until paid.