Ryan Jones Book The Trading Game

I have a question for anyone who has Ryan Jones' book entitled The Trading Game. My question is about a passage on page 86.

In the third paragraph he says "After having acquired . . ." Can anyone tell me where he got the following numbers in that paragraph: $100,000 in profits / trading 20 contracts / 4 years?

I have read this book thoroughly, and I cannot tie that paragraph to anything he discusses earlier. Any help would be much appreciated. :o
I don't know about the book or what the author trades. But is 100K over 4 years trading 20 contracts supposed to be impressive?