I didn't use a spreadsheet and used good old fashioned "lets do it the long way"... I came up with 169.
I started at 100 and got myself into a rhythm with the calculator....
100-0.5% * -.5% * -.5% * and so on... the -.5% I did with a calculator with my right hand.
the star denotes me with my left hand typing a key in notepad with my left... i got into the 4 calculator taps then on 5 I hit a key... Every now and then I noted where I was up to so that if i DID make a typing error on the calculator (i hate those things, lol) then i would be able to go back to my last KNOWN point and try agin.
I added up all the keystrokes (I pressed "1" each time as soon as I hit the % button on the calculator) and then checked it a few more times (although mental arithmetic has always been easy for me... it's the dexterity and keying accuracy that would let me down on something like this) ......
....... and submitted 169.
Its a little alarming that some have gotten 139 as i know I cannot have hit the 1 a whole 30 times more than I did... however, OK maybe I went wrong somewhere in my "recording" efforts....
hmmm.... if someone else gets the same result as me i'll feel a little better