To go with my post on pay for years of experience of federal archaeologists here is a break down in pay and number of federal archaeology jobs, both temporary and permanent. The data was gathered from FedScope. Only positions listed as archaeology 0193 are used, however there are several other archaeology based positions but sometimes they are characterized as museums, anthropology, general social scientist etc. these are missed. Key- most archaeology aids are listed as 0102 social scientists so the jobs listed here will not reflect the season shovelbum jobs GS 3 or 4. Fedscope recently started releasing numbers quarterly instead of annually but to keep the data the same all data is from the September data releases. There are some fluctuations in jobs throughout the year but not much (couple of dozen).
There is creep in pay for the last few years even though pay is suppose to be frozen for federal employees (edit- informed that the step system is still working. Fed. jobs you get yearly raise, steps even if you do not move up grades. This is what is most likely causing the slight increase in pay).
The change is most likely people change jobs within the federal system, upgrading their pay. The vast majority of federal archaeologists make under $90,000 a year but that is still really good money. Here are the numbers-