Hmm, you could be onto something; looks like my "GTL" per paycheck has crept up a bit compared to what I remembered, though still a lot less than yours.
Imputed income from life insurance over $50,000 will increase every five years, for the most part, becoming much more significant as you get older. From
Publication 15-b:
Table 2-2. Cost Per $1,000 of Protection for 1 MonthAge CostUnder 25 ................................. $ 0.05
25 through 29 ............................. 0.06
30 through 34 ............................. 0.08
35 through 39 ............................. 0.09
40 through 44 ............................. 0.10
45 through 49 ............................. 0.15
50 through 54 ............................. 0.23
55 through 59 ............................. 0.43
60 through 64 ............................. 0.66
65 through 69 ............................. 1.27
70 and older ............................... 2.06