The state’s booming economy is getting the credit for a drop in the number of uninsured motorists. The Missouri Department of Insurance reports the number of uninsured vehicles dropped from slightly over 9% in 1998 to 7.3% last year. Department of Insurance spokesman Randy McConnell says a strong state economy should get much of the credit. Increasingly tougher state law also should get some of the credit, says McConnell. The highest percentage of uninsured motorists reside in St. Louis, at 28%.