Display a limited number of sorted annotations in Mapview

I have an NSArray of 500 annotations, and I basically want to show only the ten closest annotations to the user (the rest will not be added to Mapview)

How should I do it?

Here is my code:

-(void) loadAndSortPOIs {
 [poiArray release];
 nextPoiIndex = 0;
 NSString *poiPath = [[NSBundle mainBundle] pathForResource:@"annotations"
              ofType:@"plist"];
 poiArray = [[NSMutableArray alloc] initWithContentsOfFile:poiPath];
 CLLocation *homeLocation = [[CLLocation alloc] 
        initWithLatitude:homeCoordinate.latitude
        longitude:homeCoordinate.longitude];
 for (int i = 0; i < [poiArray count]; i++) {
  NSDictionary *dict = (NSDictionary*) [poiArray objectAtIndex: i];
  CLLocationDegrees storeLatitude = [[dict objectForKey:@"workingCoordinate.latitude"] doubleValue];
  CLLocationDegrees storeLongitude = [[dict objectForKey:@"workingCoordinate.longitude"] doubleValue];
  CLLocation *storeLocation = [[CLLocation alloc]
          initWithLatitude:storeLatitude
          longitude:storeLongitude];
  CLLocationDistance distanceFromHome = [storeLocation distanceFromLocation: homeLocation];
  [storeLocation release];


  NSMutableDictionary *mutableDict = [[NSMutableDictionary alloc]
           initWithDictionary:dict];
  [mutableDict setValue:[NSNumber numberWithDouble:distanceFromHome]
        forKey:@"distanceFromHome"];
  [poiArray replaceObjectAtIndex:i withObject:mutableDict];
  [mutableDict release];

 }


// now sort by distanceFromHome

 NSArray *sortDescriptors = [NSArray arrayWithObject:[[[NSSortDescriptor alloc] initWithKey:@"distanceFromHome" ascending:YES] autorelease]];

 [poiArray sortUsingDescriptors:sortDescriptors];
 NSLog (@"poiArray: %@", poiArray);

 [homeLocation release];

EDIT: I added this to my code, but it still doesn't work ...

- (void) displayPois {
    [mapView removeAnnotations: mapView.annotations];
for(int i = 0; i < 10; i++) {
    NSDictionary *poiDict = [poiArray objectAtIndex:nextPoiIndex++];
    CLLocationCoordinate2D poiCoordinate;
    poiCoordinate.latitude = [[poiDict valueForKey:@"workingCoordinate.latitude"] doubleValue];
    poiCoordinate.longitude = [[poiDict valueForKey:@"workingCoordinate.longitude"] doubleValue];
    MyHomeAnnotation *poiAnnotation = [[MyHomeAnnotation alloc]
                                       initWithCoordinate:poiCoordinate
                                       title:[poiDict valueForKey:@"Subtitle"]
                                       ];
        [mapView addAnnotation:poiAnnotation];
        [self loadAndSortPOIs];
    [poiAnnotation release];

    }   [self adjustMapZoom];
}