Optimize an existing Python script by improving its runtime performance.
import time

start = time.time()

def foo(): 
 for _ in range(1000): 
  print('Hello World')

foo()

end = time.time()

print('Time Taken:', end - start)
import time 

start = time.time()

def foo(): 
 for i in range(1000): 
  print('Hello World', i)

foo()

end = time.time()

print('Time Taken:', end - start)