This is an excellent point and, in retrospect, an obvious oversight. How about this (prices in BTC):
Xcurrency:
ATH 0.00315
Current 0.000193
Percentage Decline: 93.87%
Cloakcoin:
ATH 0.00305
Current 0.000224
Percentage Decline: 92.66%
BitcoinDark:
ATH 0.0135
Current 0.00371
Percentage Decline: 72.52%
Blackcoin:
ATH .000723
Current 0.0000613
Percentage Decline: 91.52%
Litecoin:
ATH 0.042
Current 0.0061
Percentage Decline: 85.47%
Paycoin:
ATH 0.0404
Current 0.000586
Percentage Decline: 98.55%
...COMPARE TO...
Dash (Darkcoin)
ATH 0.02685
Current 0.01283
Percentage Decline: 52.22%
...AND JUST FOR FUN!...
Monero:
ATH 0.0079
Current 0.00213
Percentage Decline: 73.04%
I disagree with how you express the % decline.
Monero for example has declined to 27% of it's all time high, (saying 73% is misleading)
And it has reduced to
3.7 times its peak value
I got a bigger one for you: Quarkcoin :
This hit an ATH of 0.0003 btc and now is 0.0000027 btc
So quarkcoin has declined to only 0.9 % of it's all time high.
And it has reduced a staggering
111 times it's peak price !!
And everybody's all round favourite, none other than our volcano loving auroracoin.
This hit an ATH of .12 btc and is now 0.0002 btc
so auroracoin has declined to only 0.17% of it's all time high.
And it has reduced to a record
600 times less than its peak value!!!
As you point out, Dash has only reduced to roughly half its all time high measured in bitcoins and measured in dollars its about 20% of the peak of $15 (when bitcoin itself was much higher so weighting it up more of course)