SPRINGFIELD — Thanks to the recent income tax increase, the continuing effect of a tax amnesty program and higher than expected sales tax proceeds, Illinois had its best-ever May month for revenue.

Total state source revenue (including primarily income and sales taxes) last month was $2.381 billion, up $656 million or 38 percent from last May. The previous record-holder for May revenue was in 2007 when state source revenue was $2.298 billion.

Last May's total of $1.725 billion in state source revenue was the lowest in six years.

Since that time the state has enacted a tax amnesty program and increased personal and corporate income taxes by 67 percent. So far this fiscal year (which ends June 30), total state source revenue is up $3.5 billion, or 17.5 percent.

But because of a reduction of more than $800 million in federal funds in the last year, total general funds are up $2.4 billion or 10 percent.

For May, total federal source money was down $45 million from last May, but the "big three" in state source revenue were up substantially. Personal income tax collections were up $595 million, or 85 percent, corporate income tax collections were 62 percent greater and sales tax revenue increased 7.6 percent.

The personal income tax and sales tax revenues are somewhat higher than anticipated, according to Jim Muschinske, revenue manager at the state's Commission on Government Forecasting and Accountability.

"The sales tax is actually doing quite well," said Muschinske. "It's up 8.3 percent so far this fiscal year. We had projected an increase of 6.2 percent. That's pretty encouraging considering that economists say that two-thirds of the economy is driven by consumer spending."

Part of the sales tax increase is tied to the tax amnesty program that went into effect last fall, Muschinke acknowledged. But he said the projected 6.2 percent increase included the amnesty.

"Overall revenue is doing better than expected," he said. "But we're in a soft patch of the economic recovery, particularly with stagnant employment growth," he said. "The recovery isn't as robust as it was six months ago. It's not a nice, linear recovery but it seldom is."