It has been a good 10 years for those in the upper crust of Malaysian society, with the number of millionaires more than doubling from 19,900 in 2005 to 41,750 in 2015.

This is according to the Knight Frank Wealth Report, which measures the net assets of individuals across the world.

To top it off, the figure is of Malaysians who are millionaires in US dollar terms, based on a measure of their net assets, excluding their primary residence.

This, when the median household income for Malaysia is RM4,585.

The same trend persists in the “multi-millionaires” category, which measures those worth more than US$10 million (RM41.54 million).

In 2005, there were 1,200 people in this category. Last year, the number more than doubled to 2,520.

The same can be said for the billionaires club, where 12 individuals were recorded to be worth more than US$1 billion (RM4.15 billion) last year.

Last year, Mokhzani Mahathir ( picture above ) was revealed to be among the members of Malaysia's billionaires club in a survey conducted by Forbes, though his wealth did not touch US$1 billion then.

Malaysia lags in the number of billionaires compared with its neighbours Singapore (22 in 2015) and Indonesia (16 in 2015).

However, Malaysian investors are among the top in Asia Pacific to invest in Western economies, the Knight Frank Wealth Report 2016 released yesterday said.

Happily, the millionaires club is expanding further.

The Wealth Report estimates that the number of high net worth individuals in Malaysia is likely to grow by 64 percent by 2025.

Ultra rich may move out of Malaysia

However, unhappily for the Malaysian economy, many of the ultra rich might be taking their bags of money away to greener pastures.

Knight Frank's survey on wealth advisers in Malaysia found that 26.3 percent said their clients are considering changing their country of residence.

The question put was related to the sentiments of the wealth advisers over the next 10 years in an environment with increasing wealth mobility and globalisation.

The results of this survey showed that 26.3 percent of the wealth advisers in Malaysia cited their clients are considering permanently changing their domicile or country of residence over the next 10 years.

The global average is15.6 percent, with the Asia average being 18.4 percent. Across the Asia Pacific region, China respondents scored the highest in this survey, at 32.1 percent.