下面是我这边跑出的一段apache bentch日志，可看到 "Time per request"=689.946，这个值比Total max （680）还大，是否应该将 "Time per request"当然平均响应时间，还是将"Total mean"当做平均响应时间？
为什么Time per request会比Total max的值还要大？
Concurrency Level: 1000
Time taken for tests: 0.690 seconds
Complete requests: 1000
Failed requests: 0
Write errors: 0
Total transferred: 355000 bytes
HTML transferred: 7000 bytes
Requests per second: 1449.39 [#/sec] (mean)
Time per request: 689.946 [ms] (mean)
Time per request: 0.690 [ms] (mean, across all concurrent requests)
Transfer rate: 502.47 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 0 10 11.8 0 30
Processing: 7 110 186.3 19 658
Waiting: 6 110 186.4 19 658
Total: 9 120 194.1 20 680
Percentage of the requests served within a certain time (ms)
50% 20
66% 54
75% 243
80% 248
90% 254
95% 675
98% 678
99% 679
100% 680 (longest request)