Note 6 - Income Taxes (Tables)

12 Months Ended

Mar. 31, 2019

Notes Tables

Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]

	Year Ended March 31
	2019			2018
Current taxes
Federal	$	3,107,376		$	5,899,574
State		125,796			160,670
Deferred taxes
Federal		(30,012	)		31,800
State		(1,257	)		4,108
Income tax provision	$	3,201,903		$	6,096,152

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

	Year Ended March 31
	2019			2018
Tax expense at U.S. statutory rate	$	3,719,066		$	6,282,771
State income taxes, net of Federal benefit		95,430			103,240
Domestic manufacturing deduction		-			(495,361	)
Foreign-derived intangible income deduction		(555,256	)		-
Municipal interest		-			(1,378	)
Tax Reform Act effect on deferred tax assets		-			206,693
Other		(57,337	)		187
Income tax provision	$	3,201,903		$	6,096,152

Schedule of Deferred Tax Assets and Liabilities [Table Text Block]

	March 31
	2019		2018
Paid time off accrual	$	55,900	$	59,171
Inventory reserve		41,572		41,572
Depreciation and amortization		112,125		81,385
Stock-based compensation deductions		62,671		55,886
Unrealized loss on marketable securities		23,170		273,360
Other		58,297		61,281
Deferred tax assets	$	353,735	$	572,655