Ok I shouldn't say it's zero, but negligible, not much higher than zero. I especially objected to you using 20%, etc. You're talking a fraction of a percent, so it's actually not all that useful to talk about. Nice try though.
Not useful? How about you post the first 13 digits of your 16 digit credit card number. That means I'd have a 1 in 1000 chance (.1%) to guess your credit card number. Care to try me?