85. Timer Calculations

What will be the duty cycle of the PWM signal generated on pin 9 and pin 10 of Arduino UNO, 
after executing the following code?

Note: Arduino clock frequency is 16MHz.

Code:

void setup() {
  pinMode(9, OUTPUT);  // OC1A (PWM output)
  pinMode(10, OUTPUT); // OC1B (PWM OUTPUT)
 
  // Configure Timer1 for Fast PWM, Non-Inverting, ICR1 as TOP
  TCCR1A = (1 << WGM11);  
  TCCR1B = (1 << WGM12) | (1 << WGM13);  

  // Non-Inverting PWM on OC1A (Pin 9)and OC1B (Pin 11).
  TCCR1A |= (1 << COM1A1) | (1 << COM1B1);  

  // Set Prescaler = 1 (No prescaling, 16MHz clock)
  TCCR1B |= (1 << CS10);  

  // Set TOP value (ICR1) to control PWM frequency
  ICR1 = 15999;  // PWM Frequency = 16MHz / (1 * (15999 + 1)) ≈ 1kHz
 

  OCR1A = 3999;  // pin 9 
  OCR1B = 1999;  // pin 10
}

void loop() {
}