Different load test statistics beetween soapUI and Azure web service hosting

Hi, everybody

I'm using SoapUI Load testing of my web site deployed on Azure hosting. 

I've done a load test for 60 seconds and used Thread strategy with params: start threads = 10, End Threads =20

In LoadTest Options I set "Calculate TPS/BPS" as based on actual time passed. That means: 

• TPS: CNT/Seconds passed, i.e. a TestCase that has run for 10 seconds and handled 100 request will get a TPS of 10

As a result of Load test I've got 1.56 tps for my web site.

After that I downloaded detail statistic as a CSV file and calculated statistic by hand as CNT/Secons passed and got TPS<0,88

After that I opened SoapUI log file and calculated HTTP responses - 156 for 60sec of test. So TPS  is 2,6

After that I opened Azure panel and got 159 HTTP responses for 60sec. So TPS is 2,65

I've executed only one instance of loadtest. Could me anybody answer, why is so different result beetween soapUI test statistics and handmade calculation?