Is this a good Benchmark?

Code:

Failed requests:        932
  (Connect: 0, Receive: 0, Length: 932, Exceptions: 0)

It means the length of the response was different. You must benchmark the page which does not change its length (bytes) if you don't want to see the failure.

If you use ab v2.4.7 or later, you can add -l option. It does not report errors if the length of the responses is not constant.
See https://httpd.apache.org/docs/2.4/programs/ab.html

Thank you very much for the hint, dear Kenjis. Here is the output with the "-l":

Code:

$ ab -n 1000 -c 10 -v2 -l http://clinicadecot.org/rehabilitacion

Server Software:        Apache
Server Hostname:        clinicadecot.org
Server Port:            80

Document Path:          /rehabilitacion
Document Length:        Variable

Concurrency Level:      10
Time taken for tests:   8.148 seconds
Complete requests:      1000
Failed requests:        0
Total transferred:      15607000 bytes
HTML transferred:       15062000 bytes
Requests per second:    122.73 [#/sec] (mean)
Time per request:       81.478 [ms] (mean)
Time per request:       8.148 [ms] (mean, across all concurrent requests)
Transfer rate:          1870.59 [Kbytes/sec] received

Connection Times (ms)
             min  mean[+/-sd] median   max
Connect:        1    3   1.4      3       9
Processing:    46   78  44.8     71     530
Waiting:       29   57  43.4     51     489
Total:         49   81  44.8     74     533

Percentage of the requests served within a certain time (ms)
 50%     74
 66%     83
 75%     84
 80%     86
 90%     96
 95%    102
 98%    115
 99%    493
100%    533 (longest request)

Now it looks much better.
Thank you for your input!