How many nine digit binary numbers do not have any consecutive zeros?

Please show work.How many nine digit binary numbers do not have any consecutive zeros?
there are 89 of them. they are:





170 171 173 174 175 181 182 183 186 187 189 190 191 213 214 215 218 219 221 222 223 234 235 237 238 239 245 246 247 250 251 253 254 255 341 342 343 346 347 349 350 351 362 363 365 366 367 373 374 375 378 379 381 382 383 426 427 429 430 431 437 438 439 442 443 445 446 447 469 470 471 474 475 477 478 479 490 491 493 494 495 501 502 503 506 507 509 510 511

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