Statements of Income (Unaudited) - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Revenue
Product sales	$ 6,814,384	$ 6,436,672	$ 12,665,598	$ 14,172,537
Contract research and development	488,155	843,085	1,344,713	1,428,139
Total revenue	7,302,539	7,279,757	14,010,311	15,600,676
Cost of sales	1,740,814	1,644,514	3,125,992	3,638,442
Gross profit	5,561,725	5,635,243	10,884,319	11,962,234
Expenses
Selling, general, and administrative	343,688	524,631	733,603	1,009,395
Research and development	768,188	628,962	1,526,556	1,309,963
Total expenses	1,111,876	1,153,593	2,260,159	2,319,358
Income from operations	4,449,849	4,481,650	8,624,160	9,642,876
Interest income	430,983	468,531	868,717	954,329
Income before taxes	4,880,832	4,950,181	9,492,877	10,597,205
Provision for income taxes	1,575,635	1,639,386	3,055,135	3,483,184
Net income	$ 3,305,197	$ 3,310,795	$ 6,437,742	$ 7,114,021
Net income per share – basic (in dollars per share)	$ 0.68	$ 0.68	$ 1.33	$ 1.46
Net income per share – diluted (in dollars per share)	0.68	0.68	1.33	1.46
Cash dividends declared per common share (in dollars per share)	$ 1	$ 1	$ 2	$ 2
Weighted average shares outstanding
Basic (in shares)	4,835,564	4,855,398	4,835,289	4,858,557
Diluted (in shares)	4,837,819	4,858,133	4,837,293	4,862,431