diff --git a/README.md b/README.md
new file mode 100644
index 0000000..ad078f8
--- /dev/null
+++ b/README.md
@@ -0,0 +1,84 @@
+# zoxide
+
+[![crates.io](https://img.shields.io/crates/v/zoxide)](https://crates.io/crates/zoxide)
+
+A cd command that learns your habits
+
+## Introduction
+
+`zoxide` is a new `cd` alternative inspired by [`z`](https://github.com/rupa/z) and [`z.lua`](https://github.com/skywind3000/z.lua). It keeps track of the directories you use most frequently, and uses a ranking algorithm to navigate to the best match.
+
+## Examples
+
+```sh
+z foo       # cd to top directory matching foo
+z foo bar   # cd to top directory matching foo and bar
+
+z foo/      # can also cd into actual directories
+
+zi foo      # cd with interactive selection using fzf
+
+zq foo      # echo the best match, don't cd
+
+za /foo     # add /foo to the database
+zr /foo     # remove /foo from the database
+```
+
+## Getting started
+
+### Installing `zoxide`
+
+If you have Rust, this should be as simple as:
+
+```sh
+cargo install zoxide
+```
+
+Otherwise, try the install script:
+
+```sh
+curl --proto '=https' --tlsv1.2 -sSf https://raw.githubusercontent.com/ajeetdsouza/zoxide/master/install.sh | sh
+```
+
+If you want the interactive fuzzy selection feature, you will also need to install [`fzf`](https://github.com/junegunn/fzf.git).
+
+### Adding `zoxide` to your shell
+
+#### zsh
+
+If you use a package manager, installation should be as simple as adding `ajeetdsouza/zoxide` to your configuration. If you'd rather not use a package manager, simple include the following in your `.zshrc`:
+
+```sh
+_zoxide_precmd() {
+    zoxide add
+}
+
+precmd_functions+=_zoxide_precmd
+
+z() {
+    if [ $# -ne 0 ]; then
+        _Z_RESULT=$(zoxide query "$@")
+        case $_Z_RESULT in
+            "query: "*)
+                cd "${_Z_RESULT:7}"
+                ;;
+            *)
+                echo "${_Z_RESULT}"
+                ;;
+        esac
+    fi
+}
+
+alias zi="z -i"
+
+alias za="zoxide add"
+alias zq="zoxide query"
+alias zr="zoxide remove"
+```
+
+## Configuration
+
+### Environment variables
+
+- `$_ZO_DATA`: sets the location of the database (default: `~/.zo`)
+- `$_ZO_MAXAGE`: sets the maximum total rank after which entries start getting deleted
diff --git a/src/db.rs b/src/db.rs
index 6ef2eac..b008b8f 100644
--- a/src/db.rs
+++ b/src/db.rs
@@ -79,7 +79,7 @@ impl DB {
         let sum_age = self.dirs.iter().map(|dir| dir.rank).sum::<Rank>();
 
         if sum_age > max_age {
-            let factor = max_age / sum_age;
+            let factor = 0.9 * max_age / sum_age;
             for dir in &mut self.dirs {
                 dir.rank *= factor;
             }