STATEMENTS OF CASH FLOWS (Unaudited) - USD ($)	9 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
OPERATING ACTIVITIES
Net income	$ 11,172,142	$ 13,311,718
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation	241,816	231,749
Bonds discount amortization	(212,554)	(75,676)
Provision for credit losses	0	9,514
Stock-based compensation	137,906	129,392
Deferred income taxes	(371,436)	(847,235)
Non-cash operating lease credit	(63,322)	(20,039)
Changes in operating assets and liabilities
Accounts receivable	1,789,769	4,268,102
Inventories	(629,039)	(932,801)
Prepaid expenses and other assets	(47,132)	66,154
Accounts payable	27,529	(111,011)
Accrued payroll and other	(217,626)	(914,836)
Net cash provided by operating activities	11,828,053	15,115,031
INVESTING ACTIVITIES
Purchases of fixed assets	(1,162,790)	(16,731)
Purchases of marketable securities	(11,279,773)	(6,103,185)
Proceeds from maturities of marketable securities	10,205,000	8,400,000
Net cash provided by (used in) investing activities	(2,237,563)	2,280,084
FINANCING ACTIVITIES
(Payments on) proceeds from exercise of stock options	114,162	117,527
Payment of dividends to shareholders	(14,502,518)	(14,497,628)
Net cash used in financing activities	(14,388,356)	(14,380,101)
Increase (decrease) in cash and cash equivalents	(4,797,866)	3,015,014
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	5,485,684	4,684,910
Supplemental disclosures of cash flow information
Cash paid during the period for income taxes	$ 2,782,289	$ 3,685,861