Basically, to find the percent decrease, we first have to find the percent that it is in:
1576n = 1377
n = 1377/1567
(I used a calculator, if you want me to show work, just ask)
0.8787
This is 87.874%
We subtract this by 100%:
100 - 87.874
12.126%
We need to round to the nearest tenth, so:
12.13%
Alec had a 12.13% drop of visitors on his website