SECTION 1. The provinces of the Philippine Islands are hereby divided into the following classes:
First class-A: The provinces that have obtained an average total revenue of five hundred thousand pesos or more per annum for five consecutive years;
First class-B: The provinces that have obtained an average total revenue of four hundred thousand pesos or more per annum, but less than five hundred thousand pesos, for five consecutive years;
First class: The provinces that have obtained an average total revenue of three hundred thousand pesos or more per annum, but less than four hundred thousand pesos, for five consecutive years;
Second class: The provinces that have obtained an average total revenue of two hundred thousand pesos or more per annum, but less than three hundred thousand pesos, for five consecutive years;
Third class: The provinces that have obtained an average total revenue of one hundred thousand pesos or more per annum, but less than two hundred thousand pesos, for five consecutive years;
Fourth class: The provinces that have obtained an average total revenue of fifty thousand pesos or more per annum, but less than one hundred thousand pesos, for five consecutive years;
Fifth class: The provinces that have obtained an average total revenue of less than fifty thousand pesos per annum for five consecutive years:
Provided, That, in computing the average total revenue, all receipts in the form of aid or allotments from the Insular Treasury, except the internal revenue allotment under the provisions of section four hundred ninety-one of Act Numbered Twenty-seven hundred and eleven shall be excluded.