Lobbying is a very lucrative business. But for some it’s more than very lucrative: It’s million-dollar lucrative.

Between 1998 and 2012, 799 lobbyists working at Washington firms have been associated with $1 million or more in annual revenue at least once (in constant 2012 dollars). And between 1998 and 2010, the number of million-dollar firm lobbyists increased almost four-fold, from 71 to 277. That number, however, has declined since then, falling back to 207 in 2012.

Each year’s list, however, tends to be a little different. The plurality of million-dollar lobbyists — 31 percent (or 250 individuals) – only show up once in the million club. Add in the 157 who only show up twice, and just more than half were brief members of this elite stratum of lobbyists.

At the high end, three lobbyists show up in all 15 years, and another four show up in 14 of the 15 years. The table below lists the lobbyists who were associated with one million dollars in revenue or more at least 12 of the last 15 years. It is worth noting that of these 19 lobbyists, only one — Liz Robbins — is female. Additionally, two are former members of Congress — Vic Fazio and Robert Livingston, both Republicans.

Increasingly, the overwhelming majority of million-dollar lobbyists are those with former government experience, be they former government staff or former members of Congress. In 1998, 43.1 percent (31 individuals) of the 72 million-dollar lobbyists reported government experience somewhere in their lobbying forms. By 2012, the share had grown to 79.7 percent of the million-dollar lobbyists.

While the number of million-dollar lobbyists without reported government experience has more or less stayed the same, the number of million-dollar lobbyists with reported government experience has increased steadily, going from 31 in 1998 to 201 in 2010, though falling slightly to 165 in 2012.

Looked at another way in Figure 3, the share of active firm lobbyists associated with at least one million in revenue varies substantially based on background. Only about two percent of lobbyists without reported government experience are likely to be associated with a million dollars in a given year. By contrast, the share of lobbyists with government experience reaching the million-dollar threshold is generally between seven and 10 percent.

All of this is consistent with what we found earlier this week: Lobbyists with government experience earn substantially more than those without government experience, and that all of the growth in both personnel and revenue in the for-hire lobbying business can be accounted for by growth in revolving door lobbyist activity.