[maxsanic]

I not sure where you get 25% figure, because if so median wage and household should way higher.

https://blog.seedly.sg/median-income-sin...-increase/
 Data exclude full-time National Servicemen.
Data are for mid-year.
Residents refer to Singapore Citizens and Permanent Residents.
Gross monthly income from work refers to income earned from employment. For employees, it refers to the gross monthly wages or salaries before deduction of employee CPF contributions and personal income tax. It comprises basic wages, overtime pay, commissions, tips, other allowances and one-twelfth of annual bonuses. For self-employed persons, gross monthly income refers to the average monthly profits from their business, trade or profession (i.e. total receipts less business expenses incurred) before deduction of income tax.
As data are captured from a sample survey, year-on-year income changes are prone to fluctuations and should always be interpreted cautiously. Income growth studied over more extended periods (e.g. 5 or 10 years) smooths out these fluctuations and hence provides a more direct indication of income growth.

https://stats.mom.gov.sg/pages/income-su...table.aspx

Official number median wage include PRs which generally known to earn more than Sporeans 
and the wage include bonus which some get few months while others get none. 

If 25% holds water, then a company should see few workers. 
eg a company 2 manager, 2 senior engineer , 2 engineer, 2 technicians, no room for HR, admin clerk, delivery etc 
Is it common?

As I explained earlier, I am simply extrapolating as the government does not publish 75th percentile numbers. I cannot know for sure, but if you have a different view of how the extrapolation should be modeled, I am open to suggestions.

As for your comment on employee demographic of a typical company, I think it's a bit hard to generalize what a typical company looks like because it varies significantly. For e.g. in a labour intensive company you will likely have less than 10% of the population who make above $8k based on the quoted government definition. On the other hand in a knowledge intensive company, it is likely most of the employees earn above $8k.

For e.g. in an area that I am more familiar with i.e. a typical Asia Pacific / Asia Middle East RHQ of a foreign MNC, I would say the split is around 60 : 40. About 60% above $8k (managers / analyst & above) and the other 40% below (execs, admin, clerks etc.) But like I said it will vary significantly from company to company.