I have bot h a Vodafone ADSL connection, and a UFB connection

I use my orcon fibre connection until the data has been reached, and then swap to Vodafone ADSL connection in which the modem is fully powered down....

However after reading another thread, with a usage query, i thought i'd check if our usage metre does the same and it has. i swapped over to that connection on the 15th of this month. as you can see thats when it peaks again....

Heres a pasted version of the usage we've used.... 

28-May-2013 1088.753 
29-May-2013 495.787 
30-May-2013 216.794 
31-May-2013 729.729 
01-Jun-2013 228.633 
02-Jun-2013 671.971 
03-Jun-2013 1923.286 
04-Jun-2013 1300.429 
05-Jun-2013 273.291 
06-Jun-2013 2194.208 
07-Jun-2013 351.072 
08-Jun-2013 177.189 
09-Jun-2013 476.698 
10-Jun-2013 299.649 
11-Jun-2013 145.222 
12-Jun-2013 117.509 
13-Jun-2013 238.421 
14-Jun-2013 194.933 
15-Jun-2013 1611.248 
16-Jun-2013 1427.313 
Today 359.806 
Total 14521.941 


Im going to turn it off for the whole of next month, and see what happens??? but is it an error? or is it a correct?