Specify count for each index in multi-index search


I am using the following query to bring back results from multiple index's and was wondering if there was a way to specify the count for each index rather than the count for all index's:

  index: ['index1', 'index2'],
                    ignore: [404, 429, -1],
                    size: 10,
                    body: {
                        query: {
                            query_string: {
                                query: searchstring


This query works but it will bring back say 5 for each index - how can i make it bring back 10 of each index that i specify?