Which region has the highest proportion of First Class municipalities?

The Department of Finance classifies provinces, cities, and municipalities according to their average annual income.
Income classes range from First Class to Sixth Class, with First Class entities earning the most and Sixth Class, the least.
Income classification for provinces start at P90 million and below (Sixth Class) running to P450 million or more (First Class). For cities, categories start at P80 million and below (Sixth Class) to P400 million or more (First Class). Municipalities are classified by income brackets from P15 million and below to P55 million or more.
One proxy for the wealth of a region is to count the number of first class municipalities, and also cities, which are also centers of wealth.
As of June 30, the Philippine Statistics Authority (PSA) lists 299 of the country’s 1,489 municipalities as First Class. With the exception of the National Capital Region (NCR) — which has only one municipality, Pateros, with the rest cities — the region with the highest number of First Class municipalities (relative to the region’s total count) is Region XII (Soccsksargen). Region XII has 30 out of 45 municipalities in the First Class. The region with the least number of municipalities in the First Class is Region VIII (Eastern Visayas). — BusinessWorld Research