def BHS_standard(err):
    """
		Computes the BHS Standard metric
		
		Arguments:
			err {array} -- array of absolute error
		
		Returns:
			tuple -- tuple of percentage of samples with <=5 mmHg, <=10 mmHg and <=15 mmHg error
    """
    
    leq5 = 0
    leq10 = 0
    leq15 = 0
    
    for i in range(len(err)):
        
        if(abs(err[i])<=5):
            leq5 += 1
            leq10 += 1
            leq15 += 1
            
        elif(abs(err[i])<=10):            
            leq10 += 1
            leq15 += 1
        
        elif(abs(err[i])<=15):            
            leq15 += 1
        
        
            
    return (leq5*100.0/len(err), leq10*100.0/len(err), leq15*100.0/len(err))