The RAND study looks at something similar, buried in the appendices (at pp.195-199 of pdf, mixed charts and graphs):

Formulation

The outcome of any given insurgency has a lot to do with the goals sought by the insurgents. Insurgents who fought for independence or for majority rule have been almost always successful once they get going (the Mau Mau rebellion in Kenya being the notable exception) (see Figure B.5 and Table B.5). They won, in no small measure, because their campaign was consistent with the postwar zeitgeist. Conversely, insurgencies fighting for secession (or autonomy) have failed more often than they have succeeded, comporting to the principle that holds today’s national borders, however arbitrarily determined, to be largely inviolable. Otherwise, the won-lost record is mixed whether the goal is establishing a Marxist or Islamic state or overthrowing the government (that is, changing the regime without necessarily changing the governing ideology).

Of note is which goals permit mixed outcomes and which do not. Such goals as independence, majority rule, Marxism, or Islamicism tend to be either-or propositions, and only four of the 34 insurgencies with such goals have resulted in a mixed outcome. Conversely, when secession/autonomy or power arrangements are at issue, the difference can often be split, and mixed outcomes have characterized 15 cases, or nearly 30 percent of such insurgencies.

The difficulties that secessionist groups have of winning against an established government are made even clearer when viewed on a case-by-case basis. Of the six insurgent losses, three were in or near the Horn of Africa, and, in two of these, Somalia and Ethiopia, a region acquired its independent (Eritrea) or quasi-independent (Somaliland) status in the wake of a multi-insurgent overthrow of the central government. [3] [3] Sudan conceded an independence referendum to its southern provinces, but whether it carries through and actually allows its oil-bearing provinces to leave remains to be determined.

The other three secessionists were clearly the beneficiaries of some major power help: Kosovo had the North Atlantic Treaty Organization (NATO) on its side; Dnistria fended off Moldova because of the support of Russia (or at least Russia’s 14th Army); and Bangladesh had India to thank.[4] [4] East Timor, which was classified as a mixed outcome, was clearly helped by the international community, which was never reconciled to the 1975 absorption of Portuguese Timor into Indonesia.

Among the seven mixed outcomes, three (Bosnia, Nagorno-Karabakh, and Georgia-Abkhazia) were achieved against governments that had not yet established themselves when challenged.

Finally, except for insurgencies seeking independence/majority rule, most of which started prior to 1980, almost a fifth of all other insurgencies, irrespective of goal, are still ongoing.
The only extensive discussion is re: secessionist insurgencies (most of the paras above quoted).

The graph and table relevant to the goals are at p.198 of pdf.

Agree that distinctions have to be made between (1) resistence to colonial situations (now pretty much a dinosaur relic); (2) resistence to foreign occupier pursuant to its recent war against an indigenous incumbant government; and (3) resistence to substantial foreign presence in aid of an indigenous incumbant government.

Regards

Mike