operation property has three values insert, delete and update by which you can get number of additions, deletions and updates. :) I am using following query for the same.
[{
"operation": null,
"source": {
},
"from:timestamp>=": "2012-11-12T00:00:00.000Z",
"to:timestamp<": "2012-12-12T23:23:59.000Z",
"attribution": "/user/<username>",
"timestamp": null,
"sort": "-timestamp",
"type": "/type/link",
"limit": 1000
}]