Gotcha. There's several different sub-variations of Type I, like plunge-milled vs triangular serrations, 3 different (at least) slide roll-markings, etc.
Overall ~72K Type I and 572K total Model M's so percentage, roughly 12.5 %
Bear in mind though that the early ones had a lower survival rate, especially in nice condition.
Personally I like the first 10k, which had the Browning single date (1897) patent marking, plunge-mill cocking serrations, and no screw holding in the thumb safety.
It's the firstest and most basic version... but any Type I is special