[frik]

Caniuse.com shows the global usage share statistics (based on data from StatCounter GlobalStats for December 2015) next to each entry.

  IE 7: 0.05%

  IE 8: 1.18%

  IE 9: 0.91%

  IE 10: 0.87%

  IE 11: 6.45%

  Edge 12: 0.67%

  Edge 13: 0%

  Edge 14: 0%

For comparision:

  Chrome 47: 20.46%

  Chrome (Android) 47: 17.45%

The full list: http://caniuse.com/usage-table

IE 8, IE 9 and IE 10 are still more widely used than Win10 with its Edge browser.

Don't use flexbox for your start page, especially if you want to do business (SaaS). It will be completely broken in IE8/9 and look like shit. Corporate managers will close your website instantly.