Elastic Search using NEST Field Boosting

I am using Elastic Search in C# using the NEST strongly typed client. I have an index containing Entries:

[ElasticType(Name = "Entry", IdProperty = "Id")]
public class Entry
{
    public string Id { get; set; }
    public string Title { get; set; }
    public string Description { get; set; }
    public string Award { get; set; }
    public int Year { get; set; }
}

Where Year is the year of the entry, eg 2012, and Award is the type of Award the Entry won, which can be null.

I then want to search these Entries using boosting for different properties. In the following code, I want results to be ranked higher that match on the Title, than those that match on the Description.

private IQueryResponse<Entry> GetMatchedEntries(string searchText)
{
    return _elasticClient.Search<Entry>(
                body =>
                body.Query(q => 
                           q.QueryString(qs => 
                                         qs.OnFieldsWithBoost(d => 
                                                              d.Add(entry => entry.Title, 5.0)
                                                              .Add(entry => entry.Description, 2.0))
                           .Query(searchText))));
}

I have now been asked to Boost the results by those which have won Awards, and also Boost newer Entries (ie by the Year).

How do I do this? Is it something that needs to be done as part of the indexing service, or as part of the search?