| Geographic information | 
Geographic information:   
The following table contains certain financial information by geographic location for the six months ended June 30, 2015 and 2014:
   
 
|  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|   | Three months ended June 30, |   | Six months ended June 30, |  
|   | 2015 |   | 2014 |   | 2015 |   | 2014 |  
| United States: |   |   |   |   |   | 
 |   |   | 
 |  
| Revenues - owned units | 12,778,925 | 
 |   | 10,110,297 | 
 |   | $ | 22,504,226 | 
 |   | $ | 18,264,189 | 
 |  
| Management, incentive and royalty fee revenue | 1,496,474 | 
 |   | 1,471,336 | 
 |   | 3,000,548 | 
 |   | 2,985,969 | 
 |  
|   |   |   |   |   |   |   |   |  
| Foreign: |   |   |   |   |   | 
 |   |   | 
 |  
| Revenues - owned units | — | 
 |   | 13,911 | 
 |   | $ | — | 
 |   | $ | 13,911 | 
 |  
| Management and development fee revenue | 625,503 | 
 |   | 671,796 | 
 |   | 1,172,705 | 
 |   | 1,276,191 | 
 |   
The following table contains certain financial information by geographic location at June 30, 2015 and December 31, 2014:
   
|  |  
|  |  |  |  |  |  |  |  |  
|   | June 30, 2015
 |   | December 31, 2014
 |  
| United States: |   | 
 |   |   | 
 |  
| Net assets | $ | 15,778,258 | 
 |   | $ | 6,290,470 | 
 |  
|   |   |   |   |  
| United Kingdom: |   | 
 |   |   | 
 |  
| Net assets | $ | 4,100,069 | 
 |   | $ | 890,464 | 
 |  |