Why counter initiates the same value whenever restart the server

I am using couchbase 2.5.5 and using counter value to save the row in a sequential manner. But when I restart the server it starts the same value again

bucket.counter(documentId, 0, 10);
long nextIdNumber = _bucket.counter(documentId, 1).content();

eg:
id:value_11
id:value1_12

after restart,

id:value2_11
id_value3_12

But I need to save the DocumentID like the following after restart the server…

id:value2_13
id_value3_14

Any inputs here really appreciated!