public static String getPrimeMinister(String date)
  {
    date = date.replaceAll("-", "");
    
    DB db = _mongo.getDB(DATABASE_NAME);
    DBCollection coll = db.getCollection(COLLECTION_GOVERNMENT);
    
    BasicDBObject query = new BasicDBObject();
    query.put("start.date", new BasicDBObject("$lte", date));
    
    DBCursor cur = coll.find(query);
    cur.sort(new BasicDBObject("start.date", -1)); //.limit(1);
    
    DBObject doc = null;
    if (cur.hasNext()) {
      doc = cur.next();
      return doc.toString();
    }
    
    return "";
  }