How Much Bourbon Evaporates Over Time?

One of the neat things about how bourbon works is that it's a very time intensive process. Once the bourbon is made, the liquid is poured in a wood barrel where it sits for years or even decades. One of the challenges is that over time, like the vast majority of liquids, evaporation happens. This is commonly referred to as the Angel's Share and often produces a black fungus known as Baudoinia (see photo below from a warehouse at the Wild Turkey Distillery).

I wrote a little about how much product evaporates each year in a post about a 50 year Glenlivet 50 Year Old Single Malt. In that article, I found a quote from Harlen Wheatley, Master Distiller at Buffalo Trace where he states: 

...The angel's share is 10 percent for the first year (because whiskey is absorbing into the wood of barrel as well as evaporating), then 4 percent for the next 8 years after that, then around 3 percent per year after that

The good people at Alcademics.com did the math on a bottle of Pappy Van Winkle 23 and found that at bottling, a typical 53 gallon barrel produces a mere 14 gallons of product. As companies are producing longer and longer aged bourbons (Canadian Club 42, Michter's 20, etc.), I think it's helpful to take their work and extrapolate it to a full 50 years as a reference. The entire chart is below.

Year	Angel's Share (Percent)	Total
		53
1	0.1	47.7
2	0.04	45.792
3	0.04	43.96032
4	0.04	42.2019072
5	0.04	40.513830912
6	0.04	38.89327767552
7	0.04	37.3375465684992
8	0.04	35.8440447057592
9	0.04	34.4102829175289
10	0.03	33.377974430003
11	0.03	32.3766351971029
12	0.03	31.4053361411898
13	0.03	30.4631760569541
14	0.03	29.5492807752455
15	0.03	28.6628023519881
16	0.03	27.8029182814285
17	0.03	26.9688307329856
18	0.03	26.1597658109961
19	0.03	25.3749728366662
20	0.03	24.6137236515662
21	0.03	23.8753119420192
22	0.03	23.1590525837586
23	0.03	22.4642810062459
24	0.03	21.7903525760585
25	0.03	21.1366419987767
26	0.03	20.5025427388134
27	0.03	19.887466456649
28	0.03	19.2908424629496
29	0.03	18.7121171890611
30	0.03	18.1507536733893
31	0.03	17.6062310631876
32	0.03	17.0780441312919
33	0.03	16.5657028073532
34	0.03	16.0687317231326
35	0.03	15.5866697714386
36	0.03	15.1190696782955
37	0.03	14.6654975879466
38	0.03	14.2255326603082
39	0.03	13.7987666804989
40	0.03	13.384803680084
41	0.03	12.9832595696815
42	0.03	12.593761782591
43	0.03	12.2159489291133
44	0.03	11.8494704612399
45	0.03	11.4939863474027
46	0.03	11.1491667569806
47	0.03	10.8146917542712
48	0.03	10.4902510016431
49	0.03	10.1755434715938
50	0.03	9.87027716744595