Statements of Income - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Mar. 31, 2018 |
Mar. 31, 2017 |
Mar. 31, 2016 |
|
| Revenue | |||
| Revenue | $ 29,863,881 | $ 28,326,196 | $ 27,717,278 |
| Cost of sales | 6,274,744 | 6,078,294 | 6,616,852 |
| Gross profit | 23,589,137 | 22,247,902 | 21,100,426 |
| Expenses | |||
| Selling, general, and administrative | 1,435,592 | 1,458,598 | 1,752,962 |
| Research and development | 3,702,918 | 3,344,101 | 3,061,184 |
| Total expenses | 5,138,510 | 4,802,699 | 4,814,146 |
| Income from operations | 18,450,627 | 17,445,203 | 16,286,280 |
| Interest income | 1,558,197 | 1,650,808 | 1,890,817 |
| Income before taxes | 20,008,824 | 19,096,011 | 18,177,097 |
| Provision for income taxes | 6,096,152 | 6,147,142 | 5,884,782 |
| Net income | $ 13,912,672 | $ 12,948,869 | $ 12,292,315 |
| Net income per share – basic (in dollars per share) | $ 2.87 | $ 2.68 | $ 2.53 |
| Net income per share – diluted (in dollars per share) | 2.87 | 2.68 | 2.53 |
| Cash dividends declared per common share (in dollars per share) | $ 4 | $ 4 | $ 4 |
| Weighted average shares outstanding | |||
| Basic (in shares) | 4,841,347 | 4,836,602 | 4,850,209 |
| Diluted (in shares) | 4,846,212 | 4,838,389 | 4,852,602 |
| Product [Member] | |||
| Revenue | |||
| Revenue | $ 27,321,810 | $ 26,182,453 | $ 24,410,391 |
| Contract Research and Development [Member] | |||
| Revenue | |||
| Revenue | $ 2,542,071 | $ 2,143,743 | $ 3,306,887 |