Detected average expansion of the ME from Head et al. (2024) vs. the total detected bridge count for each northern HST-STIS series we considered. Negative expansions imply a contracted ME. The bridge-count error bars are determined as described in Appendix A.1. The green crosses denote the cases in which the magnetosphere was compressed, and red pluses show cases in which the magnetosphere was uncompressed. The grey points denote cases in which the compression state of the magnetosphere is unknown.