Ann: 2016 AGM Presentation, page-81

20% p.a. for 16 years is certainly a phenomenal investment record. I wouldn’t say it is impossible, rather very rare indeed. As we all know Warren Buffet did 20%+ for decades and the brilliant Peter Lynch did 29% for 13 years. Probably the other question that needs to be addressed is around how the returns were measured. Do you count franking credits? An arithmetic progression will normally yield a meaningfully higher p.a. return than a geometric – particularly when a GFC year is thrown in.

I am sure most on here will be aware of this already, if so skip the example below where per annum returns are listed over 6 years.

	Column 1
0	10​
1	19​
2	-38​
3	45​
4	-12​
5	16​

Average return = (10+19-38+45-12+16)/6 = 6.67% #Arithmetic
CAGR:
1.1*1.19*0.62*1.45*.88*1.16 = 1.20
1.2 = (1+x)^6
X = 0.0309 or 3.09% #Geometric

So depending on which method you use you could get wildly different answers. I am assuming by average you mean arithmetic? 20% pa. is certainly better than my 4 year record no matter which way you cut it.
As an aside calculation, 20% p.a. CAGR over 16 years gives: 1.2^16 = 18.5, i.e. 18.5 times your original investment assuming no tax or fees.

Like Madamswer, I am interested in your strategy. I have had a look at your postings and it seems you invest mainly in small caps and most look like real companies earning profits.