enumerate environment starting on last item number and step down up to the first

Question

I would like to produce an enumerated list of items that starts on the last number and stepping down until the counter is 1:

\documentclass{article}
\begin{document}
\begin{enumerate}
 \item 1st item
 \item 2nd item
 \item 3rd item
 \item last item
\end{enumerate}

The desired output would be:

4- 1st item,

3- 2nd item,

2- 3rd item,

1- last item.

i.e. starting on 4 (total items on list) and decreasing counter until 1. That's because it is a list of tasks, most recent on first position but with the number of the last task carried out.

Any help would be appreciated. Thanks