x => r2017.11.06-insert-latency.log 
y => 9acbd68815499fc7f8fbb5931d643b8fd7804a80-insert-latency.log 

         n min     max median  average     stddev p99
x 56520884 0.5    4.00   1.05 1.184553  0.5140824   3
y 56520884 0.5 3463.95   1.05 1.538691 19.1133444   3

               0.8                 1                 1.2               1.4      
 |--------------+------------------+------------------+-----------------+------|
                                       +                                        
1                                      |                                        
                                       +                                        
                                       +                                        
2                                      |                                        
                                       +                                        
Legend: 1=data$x, 2=data$y

At 95% probablitiy:
===> average is statistically significant     (p=0.000000, diff ~0.354138)
===> variance is statistically significant    (p=0.000000)