[R] not plotting when non-existent

[Luis Ridao Cruz]

R-help,

I'm trying to plot the following:

     year      lgd
1  1986 136.97479
2  1987  69.10377
3  1988  67.66744
4  1989  71.60316
5  1990  62.06897
6  1992   6.25000
7  1993  27.72021
8  1995  23.83648
9  1996  10.29412
10 1997  95.67487
11 1998  82.09367
12 1999  56.60401
13 2000  29.80864
14 2001  23.77535
15 2002  48.30378
16 2003  83.47571
17 2004  74.58711

There are 2 missing years 1991 and 1994.
Is it possible to plot this simple data set so that there is not "line"
connection between
1990-1992 and 1993-1995?

I currently use 'plot(...., type = "o", pch = 16)' 

I could as well plot 'pieces' of the vectors with "lines" but I was
wondering wether there is a simple function to achieve this.

I run on Windows XP

> version
         _              
platform i386-pc-mingw32
arch     i386           
os       mingw32        
system   i386, mingw32  
status                  
major    2              
minor    0.1            
year     2004           
month    11             
day      15             
language R  

Thank you in advance