STATEMENTS OF CASH FLOWS (Unaudited) - USD ($)	3 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
OPERATING ACTIVITIES
Net income	$ 4,097,587	$ 4,403,730
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation	75,594	77,022
Corporate bonds discount amortization	(53,219)	(17,565)
Provision for current estimate of credit losses	0	212,440
Stock-based compensation	18,442	10,536
Deferred income taxes	(147,844)	(87,000)
Changes in operating assets and liabilities
Accounts receivable	1,044,815	913,872
Inventories	(6,047)	124,848
Prepaid expenses and other assets	208,876	(10,243)
Accounts payable and accrued expenses	614,188	(602,338)
Net cash provided by operating activities	5,852,392	5,025,302
INVESTING ACTIVITIES
Purchases of fixed assets	(916,634)	(4,131)
Purchases of marketable securities	(6,580,140)	(3,937,835)
Proceeds from maturities of marketable securities	2,200,000	3,400,000
Net cash used in investing activities	(5,296,774)	(541,966)
FINANCING ACTIVITIES
Proceeds from exercise of stock options	0	117,527
Payment of dividends to shareholders	(4,833,676)	(4,830,826)
Net cash used in financing activities	(4,833,676)	(4,713,299)
Decrease in cash and cash equivalents	(4,278,058)	(229,963)
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Beginning Balance	10,283,550	1,669,896
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Ending Balance	6,005,492	1,439,933
Supplemental disclosures of cash flow information
Cash paid during the period for income taxes	$ 0	$ 1,195,542