It really depends... I started out in 2007 with a pte mfg plant, starting salary is onlt 2.8k. At the end of 2007, it was adjusted to 3k. I switched to stat board with 3.1k in 2008. After a year, I was only getting 3.2k+ while at the same time fresh grad who came in was already getting 3.5k. So i switch job again in 2010. This time to civil service, and I was offered 4k.

Imagine if I had stayed faithfully in 1 company throughout, I do not think I can get the amount of salary I am getting today. But at the same time we cannot possibly be hopping here and there every few years as it will look bad on our resume... So I guess its good to hop more when young to try out different things and settle down fast in an area you enjoy and with good prospect & stability.