A healthy boost in withholding taxes highlighted robust August revenue collections, the state finance office reported today. A 19.2 million, or 9.1% jump in withholding taxes from the previous month, helped pushed August collections to $355.9 million. That`s a $37 million increase over a year ago and $26.2 million, or eight percent, above forecast. The figures come from a state Department of Finance and Administration report. Individual income taxes and gross receipts collections also showed healthy increases. The department director said that job growth in Arkansas has been better than in many other states, which could account for much of the bump.