classSavingThrowFormulas: {
    base: {
        high: "2 + floor(@hitDice / 2)";
        low: "floor(@hitDice / 3)";
    };
    custom: {
        high: "0";
        low: "0";
    };
    mythic: {
        high: "0";
        low: "0";
    };
    npc: {
        high: "2 + floor(@hitDice / 2)";
        low: "floor(@hitDice / 3)";
    };
    prestige: {
        high: "floor((1 + @hitDice) / 2)";
        low: "floor((1 + @hitDice) / 3)";
    };
    racial: {
        high: "2 + floor(@hitDice / 2)";
        low: "floor(@hitDice / 3)";
    };
} = ...

The formulae for saving throw progressions by class type