GST is unnecessary and bad

I have been against GST since its implementation. It is unnecessary and bad for Singapore. Here are my reasons.

a) There is no need to get revenue from GST in the first place. Unlike Western countries, Singapore does not provide much in welfare benefits, e.g. old age pension or unemployment benefit.
b) The Government already collect a lot of money from ERP, COE, land sale and foreign worker's levy.

So, the government does not really need this source of revenue. The introduction of GST (from 3%, 5% to 7%) has resulted in increase in the cost of living and added additional cost in compliance and collection. This also increased the cost of doing business.

I need your help to do some research for me, as follow:

a) How much is the GST collected in each year, and also the government surplus? (This will show that GST revenue is NOT necessary for Singapore)
b) Average income in Singapore and the number of taxpayers that earn above $100,000 and $500,000 a year.

I wish to write a paper to argue that GST should be scrapped entirely (and not just removed for essential items, or to reduce to 3% - as suggested by some opposition parties).

Tan Kin Lian