Non-alphanumeric character counts for Subversion Python test code:

     total      % of all chars   % of all non-alphanumerics
     -------    --------------   --------------------------
-    32802     2.613951%        15.569510%
_    30527     2.432659%        14.489679%
'    23310     1.857545%        11.064121%
,    20720     1.651151%        9.834774%
.    19118     1.523490%        9.074383%
#    15795     1.258684%        7.497116%
=    12157     0.968776%        5.770335%
(    11952     0.952440%        5.673032%
)    11136     0.887414%        5.285716%
/    7710      0.614400%        3.659561%
"    6753      0.538138%        3.205320%
:    5430      0.432710%        2.577356%
|    1796      0.143121%        0.852474%
]    1747      0.139216%        0.829216%
[    1700      0.135471%        0.806907%
\    1548      0.123358%        0.734760%
}    1301      0.103675%        0.617521%
+    1126      0.089730%        0.534457%
{    816       0.065026%        0.387315%
*    620       0.049407%        0.294284%
$    618       0.049248%        0.293334%
>    351       0.027971%        0.166603%
!    335       0.026696%        0.159008%
%    330       0.026297%        0.156635%
<    293       0.023349%        0.139073%
;    169       0.013467%        0.080216%
?    131       0.010439%        0.062179%
@    127       0.010120%        0.060281%
`    106       0.008447%        0.050313%
&    88        0.007013%        0.041769%
^    57        0.004542%        0.027055%
~    12        0.000956%        0.005696%