This is an error. Thanks for letting us know! I’ve informed the IPUMS Health Surveys team and it should be fixed with the next data release. In the meantime, I can email you a file that should provide you with the correct values for SUPP3WT for 1994 and 1995.
We like to reward users who help us improve IPUMS by uncovering errors with a MPC mug! To claim yours, email your mailing address to ipums@umn.edu.