The Table Below Shows Hypothetical Per- Minute Cell Phone Charges

The table below shows hypothetical per- minute cell phone charges for "pay- and- talk" service over several years. $$\begin{array}{l}\begin{array} { | l | l | } \hline 2005 & 0.55 \\\hline 2006 & 0.50 \\\hline 2007 & 0.40 \\\hline 2008 & 0.35 \\\hline 2009 & 0.25 \\\hline\end{array}\\\text { TABLE 2- } 2\end{array}$$
-Refer to Table 2- 2. Assume that 2005 is used as the base year, with the index number = 100. Which of the following series is the correct set of index numbers for the per- minute cell phone charges from 2005 to 2009?

A) 1.0; 0.91; 0.73; 0.64; 0.45
B) 100; 91; 73; 64; 45
C) 0.55; 0.50; 0.40; 0.35; 0.25
D) 100%; 91%; 73%; 64% 45%
E) 55; 50; 40; 35; 25