| 
    
        
            | 
                    Closing price on 1/18/2017
                 |  |  
    
        |           
                
                    | Open | 31.30 |  
                    | High | 31.30 |  
                    | Low | 31.00 |  
                    | Volume | 106,720 |  
                    | Split-adjusted Price | 19.35 |  
                
             | 
 |  NAF Historical Quote 
            
                | Date | Change | Open | High | Low | Close | Average | Adjusted Close | Volume |  |  			
            | 1/18/2017 | -0.20 / -0.64% | 31.30 | 31.30 | 31.00 | 31.10 | 31.14 | 19.35 | 106,720 |   |  
            | 1/17/2017 | +0.10 / +0.32% | 31.20 | 31.60 | 31.20 | 31.30 | 31.37 | 19.48 | 110,880 |   |  			
            | 1/16/2017 | -0.20 / -0.64% | 31.40 | 31.40 | 31.05 | 31.20 | 31.19 | 19.41 | 115,920 |   |  
            | 1/13/2017 | -0.10 / -0.32% | 31.50 | 31.55 | 31.30 | 31.40 | 31.42 | 19.54 | 105,160 |   |  			
            | 1/12/2017 | -0.20 / -0.63% | 31.70 | 31.70 | 31.40 | 31.50 | 31.53 | 19.60 | 109,450 |   |  
            | 1/11/2017 | +0.20 / +0.63% | 31.60 | 31.80 | 31.40 | 31.70 | 31.62 | 19.72 | 111,270 |   |  			
            | 1/10/2017 | -0.10 / -0.32% | 31.60 | 31.60 | 31.30 | 31.50 | 31.45 | 19.60 | 114,040 |   |  
            | 1/9/2017 | +0.10 / +0.32% | 31.50 | 31.70 | 31.40 | 31.60 | 31.56 | 19.66 | 115,670 |   |  			
            | 1/6/2017 | -0.10 / -0.32% | 31.60 | 31.60 | 31.40 | 31.50 | 31.50 | 19.60 | 117,660 |   |  
            | 1/5/2017 | -0.10 / -0.32% | 31.70 | 31.80 | 31.50 | 31.60 | 31.63 | 19.66 | 119,680 |   |  			
            | 1/4/2017 | 0.00 / 0.00% | 31.60 | 32.00 | 31.60 | 31.70 | 31.81 | 19.72 | 131,040 |   |  
            | 1/3/2017 | +0.40 / +1.28% | 31.40 | 31.70 | 31.30 | 31.70 | 31.54 | 19.72 | 119,240 |   |  			
            | 12/30/2016 | +0.20 / +0.64% | 31.10 | 31.40 | 31.10 | 31.30 | 31.27 | 19.48 | 130,760 |   |  
            | 12/29/2016 | 0.00 / 0.00% | 31.10 | 31.30 | 31.00 | 31.10 | 31.13 | 19.35 | 99,160 |   |  			
            | 12/28/2016 | +0.10 / +0.32% | 31.00 | 31.20 | 30.90 | 31.10 | 31.08 | 19.35 | 109,530 |   |  
            | 12/27/2016 | +0.10 / +0.32% | 30.90 | 31.20 | 30.80 | 31.00 | 30.99 | 19.29 | 111,680 |   |  			
            | 12/26/2016 | 0.00 / 0.00% | 30.90 | 31.10 | 30.70 | 30.90 | 30.92 | 19.23 | 105,990 |   |  
            | 12/23/2016 | 0.00 / 0.00% | 30.90 | 31.10 | 30.80 | 30.90 | 30.94 | 19.23 | 109,420 |   |  			
            | 12/22/2016 | -0.20 / -0.64% | 31.10 | 31.30 | 30.80 | 30.90 | 31.02 | 19.23 | 113,110 |   |  
            | 12/21/2016 | 0.00 / 0.00% | 31.10 | 31.30 | 30.90 | 31.10 | 31.10 | 19.35 | 106,830 |   |  			
            | 12/20/2016 | -0.50 / -1.58% | 31.60 | 31.60 | 31.00 | 31.10 | 31.33 | 19.35 | 104,390 |   |  
            | 12/19/2016 | -0.20 / -0.63% | 31.80 | 31.90 | 31.50 | 31.60 | 31.75 | 19.66 | 118,210 |   |  			
            | 12/16/2016 | -0.10 / -0.31% | 31.80 | 32.10 | 31.70 | 31.80 | 31.87 | 19.79 | 113,290 |   |  
            | 12/15/2016 | -0.10 / -0.31% | 32.00 | 32.20 | 31.80 | 31.90 | 31.98 | 19.85 | 110,870 |   |  			
            | 12/14/2016 | +0.20 / +0.63% | 31.80 | 32.10 | 31.70 | 32.00 | 31.93 | 19.91 | 108,990 |   |  
            | 12/13/2016 | -0.60 / -1.85% | 32.40 | 32.40 | 31.50 | 31.80 | 31.88 | 19.79 | 111,710 |   |  			
            | 12/12/2016 | -0.30 / -0.92% | 32.70 | 32.70 | 32.20 | 32.40 | 32.40 | 20.16 | 94,510 |   |  
            | 12/9/2016 | -0.30 / -0.91% | 33.00 | 33.00 | 32.50 | 32.70 | 32.75 | 20.35 | 107,870 |   |  			
            | 12/8/2016 | +0.10 / +0.30% | 32.80 | 33.10 | 32.80 | 33.00 | 32.99 | 20.53 | 102,740 |   |  
            | 12/7/2016 | 0.00 / 0.00% | 32.90 | 33.10 | 32.80 | 32.90 | 32.97 | 20.47 | 113,020 |   |  |