$\ddot{\nu }$ vs. time since the preceding glitch. The horizontal dashed line indicates ${\ddot{\nu }}_{\mathrm{ref}}=0.44·{10}^{-20}{\mathrm{s}}^{-3}$. The data points were obtained by fitting Eq. (1) over a 90-day sliding window, which moved forward 20 days at each step. The full inter-glitch data span was fitted if the inter-glitch interval was shorter than 90 days. The red stars were obtained by fitting smaller windows of at least 30 d and at least eight TOAs immediately after the glitches with a recovery were detected.