Condensed Statements of Income - USD ($)	3 Months Ended		6 Months Ended
	Jul. 31, 2015	Jul. 31, 2014	Jul. 31, 2015	Jul. 31, 2014
Revenues
Royalty income	$ 2,732,892	$ 7,858,104	$ 4,048,845	$ 8,359,404
Interest income	2,469	2,256	4,525	4,391
Total revenues	2,735,361	7,860,360	4,053,370	8,363,795
Expenses	251,717	443,819	629,460	810,036
Net income	$ 2,483,644	$ 7,416,541	$ 3,423,910	$ 7,553,759
Number of units outstanding	13,120,010	13,120,010	13,120,010	13,120,010
Net income per unit (Note 2)	$ 0.1893	$ 0.5653	$ 0.2610	$ 0.5757
Distributions declared per unit (Note 3) (in dollars per unit)	$ 0.0400	$ 0.3200	$ 0.0400	$ 0.3200