Objective-C Xcode Decrementing Fluid Progress Bar

gistfile1.m

//.h
//IBOutlet UIProgressView *pv;

//.m
- (void)viewDidLoad
{
    [super viewDidLoad];

    pv.progress = 1.0;
    [self performSelectorOnMainThread:@selector(makeMyProgressBarMoving) withObject:nil waitUntilDone:NO];
    
}

- (void)makeMyProgressBarMoving {
    
    float actual = [pv progress];
    if (actual > 0) {
        //10 Seconds duration
        pv.progress = actual - ((float)0.005);

        //Update every 0.05 seconds to maintain fluidity.
        [NSTimer scheduledTimerWithTimeInterval:0.05 target:self selector:@selector(makeMyProgressBarMoving) userInfo:nil repeats:NO];
    } else {
        //Progress bar has reached zero
    }
    
}

/*
Timer interval calculation:

10 Seconds:
10 / 0.05 = 200
1 / 200 = 0.005

2 Seconds:
2 / 0.05 = 40
1 / 40 = 0.025
*/