Cannot use percentage in @keyframe rule

[clehnert-psl]

When I attempt to convert this CSS

@keyframes dash {
  0% {
    stroke-dasharray: 1,200;
    stroke-dashoffset: 0;
  }
  50% {
    stroke-dasharray: 89,200;
    stroke-dashoffset: -35;
  }
  100% {
    stroke-dasharray: 89,200;
    stroke-dashoffset: -124;
  }
}

...using sass-convert, I get Error on line 2 of (css): Invalid CSS after "": expected selector, was "0%"

I know I can change the '0%' to 'from' and '100%' to 'to', but I don't think there are any other values I can use for a percentage other than 0 or 100.

[clehnert-psl]

Thanks