Error porcentaje en express

package.json

{
  "name": "app",
  "version": "0.1.0",
  "devDependencies": {
    "apidoc": "^0.12.3",
    "del": "^1.1.1",
    "errorhandler": "^1.3.3",
    "gulp": "^3.8.10",
    "gulp-angular-filesort": "^1.1.1",
    "gulp-angular-templatecache": "^1.5.0",
    "gulp-autoprefixer": "^2.1.0",
    "gulp-bump": "^0.3.0",
    "gulp-concat": "^2.4.3",
    "gulp-css-url-rebase": "^0.2.0",
    "gulp-git": "^1.0.0",
    "gulp-inject": "^1.1.1",
    "gulp-jscs": "^1.4.0",
    "gulp-jscs-stylish": "^1.0.2",
    "gulp-jshint": "^1.9.1",
    "gulp-minify-css": "^1.0.0",
    "gulp-mocha": "^2.0.0",
    "gulp-ng-annotate": "^0.5.2",
    "gulp-nodemon": "^2.0.2",
    "gulp-open": "^0.3.2",
    "gulp-plumber": "^1.0.0",
    "gulp-rev-all": "^0.8.13",
    "gulp-sass": "^1.3.2",
    "gulp-uglify": "^1.1.0",
    "gulp-usemin": "^0.3.11",
    "gulp-util": "^3.0.2",
    "gulp-wait": "^0.0.2",
    "gulp-watch": "^4.1.0",
    "jshint-stylish": "^1.0.1",
    "main-bower-files": "^2.5.0",
    "run-sequence": "^1.0.2",
    "should": "^6.0.1",
    "streamqueue": "^0.1.2"
  },
  "dependencies": {
    "async": "^0.9.0",
    "body-parser": "^1.12.0",
    "browser-sync": "^2.5.3",
    "chalk": "^1.0.0",
    "compression": "^1.4.0",
    "cookie-parser": "^1.3.3",
    "d3": "^3.5.5",
    "express": "^4.12.2",
    "html-minifier": "^0.7.2",
    "html-pdf": "^1.2.1",
    "iconv-lite": "^0.4.11",
    "jsdom": "^5.4.2",
    "lodash": "^3.3.1",
    "method-override": "^2.3.1",
    "morgan": "^1.5.1",
    "phantomjs": "^1.9.17",
    "ripe": "^0.2.0"
  },
  "scripts": {
    "prestart": "npm install",
    "start": "node server/server.js",
    "test": "gulp test"
  }
}